Involute gear profile diagram The tooth profile shown in Fig 3. Since it has no meaning to correct the gear rack in this case, only the pinion correction is possible (axial distance, gear condition and strength parameter In this video tutorial step by step, a procedure has been used for drawing the front elevation of an involute of a spur gear profile by using the approximate Dec 1, 2018 · #engineering #tutorials The involute gear profile is the most commonly used system for gearing today, with cycloid gearing still used for some specialties su centering function. The coordinate frame Ex E y E is built with the y E -axis Involute Gears Pro/ENGINEER Wildfire 3. Pitch point: Point along the line of action that intersects the pitch circle. l-Irwolutes applied to two one-tooth gears. I am making a range of gears with different profile shifts and I want them driven so when I change the profile shift value in my table (which is a dimensionless value) it adjusts each profile shift within the value driven involute curve. You can, but to be honest I am more at a loss where or how to use the profile shift in my making of the gear. These measurements can be realised by different types of measuring devices located at a fixed position, e. This gear design article will discuss involute gears, the process of generation of an involute profile in CAD design and manufacturing by the hobbing process, as well as advantages and disadvantages of and applications for involute gears. In designing involute gear teeth. Rarely will anyone need to play with other types, such as hypoid gears. 2 as follows: Oct 31, 2018 · In mechanical engineering, the involute is used almost exclusively as a tooth form for gears. Hence, Involute gears can handle centre sifts of the gears better. Angle of pressure equal to 20 • . Diameters or [21]) on external modified involute gear teeth is presented in this technical report. Recall that the involute of a circle may be viewed as the locus of the Gear involute artifact (GIA) is a kind of measurement standard for calibrating the gear involute measuring instrument. Nine times out of ten, the approximate geometry of Toolbox spur gear will work just fine, but there are certain applications where accurate involute geometry is required. 1 - Diagram mustraUng: Three Means for TransmWing Rotary Motion from. The teeth in question are composed of an involute working profile from the outer to the form circle of the gear and of a circular fillet from the form to the root circle, replacing the conventional trochoidal fillet. The key to involute gear’s success lies in their geometry. On the other hand, involute gears can be manufactured cost-effectively due to the relatively simple tool 3. Add other gear details as they appear on the gears. The involute tooth profile is a curve formed on the outside of the base circle, and the pressure angle on the base circle is zero. This statement must of course be limited if the Jul 21, 2022 · A gear gauge has the gear tooth profile for one or more gears. Gears generally have an involute curve tooth profile. 3. Such gears are called involute gears. This can be demonstrated by at-Fig. Some gear pitch gauges are metal and can run against a gear, while some are paper and allow for visual comparison. 11. Synthetic curves are widely used in CAD software . Let us now examine the involute profile to see how it satisfies the requirement for the transmission of uniform motion. You can also add a fillet where the tooth form intersects the root circle and you can flatten the top of the gear tooth slightly. See the figure below. 1, we will detail all the values: Ek : Generation segment. from publication: Hybridization of Taguchi and Genetic Algorithm to minimize iteration for optimization of solution Download scientific diagram | Profile of skiving tool in different cross-section. Involutometry Involute Curve Fundamentals Over the years many different curves have been considered for the profile of a gear tooth. Circular pitch . The involute gear’s versatility is another reason for its widespread use. A point P on this involute can be described by the angle α, which is spanned between the straight lines GP and GT. The common normal of involute gear teeth is a straight line (AB, in Fig. from publication: Stress optimization and study of the sensitivity to geometric variations of a spur gear tooth profile | This paper Jul 2, 2020 · The most common type of gear tooth profile is the involute gear tooth profile, standard and corrected. Profile below mating point Figure3. By comparing the known gauge to an unknown gear, you can determine the gear's pitch (or module) and pressure angle. Total Involute (Profile) Variation -The total amount of profile variatien, plus to minus. Figure 5: Design profile: modified involute (example with full contour) Figure 5 is for a gear that has a barreled profile specified. A pair of helical gears or spiral bevel gears needs to have the same module and pressure angle, but in addition, you need to pay attention to the twist direction. Gears can be animated with various speed to demonstrate working mechanism Oct 18, 2024 · Choosing the right gear profile is crucial for optimizing the performance of your machinery. 1, where the tooth depth is 2. If instead, the modulem, center distance a and speed ratio i are given, then the number of teeth, z 1 and z 2, would be calculated using theformulas as shown in Table 4. As we proceed from the pinion on the electric motor to the gear on the output shaft, how do the pitch and face width vary? 1. any number of teeth, if these were manufactured with the same rack-shaped tool! Download scientific diagram | (a) Definition of a circle involute. Cyloidal. To increase the nodes path accuracy nearby the base circle, we change the nodes selection method to an equal rolling arc, shown in Eq. Table 3. That is, the envelope of line segments on gear blank is an involute of a circle. May 19, 2013 · 53) Mate the temporary axis of the second gear to the assembly top plane … Step 54: 54) … and mate the front faces of both gear wheels. The basic cutter of an involute gear has a profile in which the active segment is a straight line. This involute curve helps the gears transmit power smoothly during the The manufacturing tool profile can be specified both for the pinion and the gear rack. The result-ing involute diagram win be wavy due to the Straight-Sided Profile: Less common in modern gear systems. All calculated values in Table 4. 1 lists terms, symbols, formulas and definitions related to gear tooth profiles. from publication: Hybridization of Taguchi and Genetic Algorithm to minimize iteration for optimization of solution Mar 4, 2020 · This bit is about how to lay-out the gear tooth profile, for how many teeth to have, scroll down to ‘Working out what you need. a program can plot displacement-velocity-acceleration-jerk diagrams of a cam and then plot its contour the actual involute profile Mean prifle line Microsoft Word - gear inspection symbols. Ef:;;;; Generation segment of The involute gear type is the most commonly used gear in industry. mon base circle, so that the involute profile extends along the whole length of the tooth from the front face to the back of the cutter. The impression (or "footprint") forms the gear tooth profile. 2, whose dedendum profile is defined by the same generating circle of radius r rolling round the inside of its pitch circle. Intuitively, the start and end points are referred to as the start of active profile (SAP) and end of active profile (EAP). Gear Generator is a tool for creating involute spur gears and download them in SVG format. e. The reason for the involute profile is the fact that most external splines are manufactured by hobbing with a standard straight-sided, symmetric hob tooth profile that is fast and delivers good accuracy results. Gears with involute tooth profile are To calculate a spur gear, simply decide and input your tooth count, gear module, and pressure angle and the online spur gear DXF generator will do the rest. Involute Tooth Profile. Schematic diagram of involute gear tooth showing the polar coordinates of the involute profile (magenta) and its base circle (blue). from May 1, 2019 · When comparing the shape of profile diagrams in Fig. The following examples are involute spur gears. Right-click on the first gear wheel (the one with that has (f) in front of its name) and choose “Float”. Thus, the reference circle pressure angle value of normal section between both flanks are not quite different. An involute gear profile means that the profiles of the gear teeth are involute s of a circle, while the involute of a circle is the locus of a point on a piece of string as the string is unwrapped from a circle. Once the gears are rendered you can use the mouse scroll wheel or the slider underneath the window to zoom in and out. Gear hobbing. Thus, involute teeth are easy to manufacture; The basic rack has straight teeth and the same can be cut with simple tools. • Pick File, New, then enter < involute_gear > for the name of the new part • Pick OK in the New dialog box • Pick Insert, Model Datum, Curve, From Equation, Done This is not the case for standard gears with no deliberate backlash implemented. known as the' "base circle". Such gear wheels, predominantly with involute teeth Basics of involute tooth profile and involute gear design; Calculating involute gear geometry; Designing and drawing involute gears in a CAD program is tricky, but if you follow the steps below, the teeth will come out right every time. The involute profile is defined by the curve traced by the end of a taut string as it unwinds from a cylinder. Each gear tooth has an involute profile shaped like a spiral. Figure 5(b) shows the profile deviations of internal gears. In the case of helical gearing, a plane of action must be considered since the involute teeth vary along the gear facewidth, causing the pressure angle at Design 10'f Involute Gear 'Teeth by fellows 'Corporation Fig. indicating that the involute has its origin at the base drde, but is not limited in length. When two standard involute gears are meshed, their pitch circles are tangent to each other at the standard Jul 16, 2015 · Figure 4: Design profile: unmodified involute. If the pinion is rotated by 24° and the initial contact at the profile reference point is located at the front face of the teeth, then the back rotation of the profile has to occur as the contact moves along the face width to the back face of the teeth. 1 Tooth profile of a rack with Module 1 Addendum : 1. Fig. See the figure Nov 4, 2018 · The always identical circular pitches on the manufacturing pitch circles make it possible not only to pair “normal” gears with profile-shifted gears, but also to combine gears of any size, i. Schematic diagram of ‘Involute tester’. Figure 3 includes a sketch of the blending segments-the involute and part of the dedendum circle-by means of a third one, Γ. 1 are based upon given module m and number of teeth (z 1 and z 2). Fig. four profile traces taken around the gear at 90° intervals . Step 56: The efficiency of high-ratio planetary gear trains (PGTs) is mainly constrained by the meshing efficiency of acting gears in each stage. When precision gears are cut by modern gear-cutting machines, the accuracy with which the actual teeth conform to their theoretical shape is quite remarkable, and far exceeds the accuracy which is attained in the manufacture of most other types of machine elements. Most modern gears use a special tooth profile called an involute. The material side is below the curve. from publication: Stress optimization and study of the sensitivity to geometric variations of a spur gear tooth profile | This paper The theoretical development for profiling the cutting edges of disk cutter for cutting cylindrical gears with involute profile is formalized in such level [4], which is possible to use for Download scientific diagram | Profile of skiving tool in different cross-section. Diagram showing the gear flank and the active line of a mating gear pair. The Involute Gear Tooth Profile. This figure indicates how two involute teeth in mesh are moving to transmit rotary motion. Explore the technical profile of gear tooth with this informative diagram. NOTE: The occurrence of interference with pinion is the only disadvantage of the Involute gear profile. (See Fig. The Sep 7, 2022 · The diagram is plotted from root to tip in the direction of increasing length of roll. The most commonly used conjugate tooth curve is the involute curve (Erdman & Sandor 84). from publication: Approximation of involute curves for CAD-system processing | In numerous instances Involute Diagrams Fig. The cutting edges of a hob are straight-flanked and wrap spirally around the milling tool (similar to the thread of a screw). 3 Involute Curve. Only another part of the same involute is used. As a result, existing methods for gear generating involve the following procedures: • Establish the mathematical model of the gear drives according to the manufacturing process and gear meshing Figure below shows schematic diagram of “The Klingeluberg involute tester’ used to test gear tooth profile (an involute curve). 'Non-involute Gear Profiles' published in 'Encyclopedia of Tribology' A similar description can be made for a second gear meshing with the gear in Fig. The end section tooth profile of the offset involute cylindrical worm can be seen in the right figure of Fig. •. 4 - Effects of convex curve. Involute Gear. Thereafter, a comparative study between the gear tooth profiles using involute profile and synthetic curve profiles is presented. the involute flank of a gear profile. To reduce the profile form deviations and the difference of the profile slope Dec 6, 2012 · The theoretical shape of the tooth profile used in most modern gears is an involute. A compound gear train is formed of eight gears. Taking the line 0'fL' action for an abscissa, as in Fig. 38 Gear TechnolOOv May 3, 2009 · Advantage of Involute gear • Contacts between two mating teeth in involute gear occur in a fixed plane of action irrespective of the centre to centre distances between the gears. (See fig. Figure 1 shows tooth profiles of the S-shaped and involute Jun 22, 2008 · Interactive Involute Gear Analysis And Tooth Profile Generation Using Working Model 2 D. [Ref. The cross-sectional profile of a hob is equal to that of Sep 1, 2009 · As an example of the fillet profile optimization, different fillets were constructed for the gear pair with the standard involute tooth profile and the following parameters (Figure 3): • Number of teeth of both mating gears—24 • Dametral pitch—12 • Generating rack profile (pressure) angle—20o • Addendum coefficient—1. Pitch falls, face width rises 4. EXERCISE 4 – INVOLUTE GEARS Task 1: Create a datum curve driven by an equation. According to Fig. Pitch falls, face width falls Pitch circle: Circle along which the involute body, e. Pitch rises, face width falls 3. 38 Gear TechnolOOv n1 > 0: A regular external gear ; n1 = 0: Rack and pinion ; n1 < 0: An internal gear as used in planetary gears ; The tool also supports profile shift to reduce the amount of undercut in gears with low tooth counts. from publication: Mechanical Efficiency Jul 18, 2024 · While a physical spur gear most often uses an involute curve to define its tooth profile, the Toolbox spur gear uses a simple constant radius curve. How is the Involute Used in Gear Design? In gear design, the involute curve is used to define the shape of gear teeth. Usu-any of four profile traces taken around the gear at 90° intervals. In Figure 4, the design profile is a perfect involute, so there is no difference between Figure 4(a) and Figure 4(b). (b) A gear tooth profile. The cutter (rack) centerline is tangent to the pitch circle. A spur gear calculator uses these parameters to generate the involute tooth form that's the right size and shape to take into your CAD software, or straight to a CNC router or laser cutter. Download scientific diagram | Tooth profile shape and the path of contact: (a) involute gear pair, m = 1 mm, z1 = 20, z2 = 50; (b) S-gear pair, m = 1 mm, z1 = 20, z2 = 50, n = 2. from publication: Comparison on torsional mesh stiffness and contact Involute Gear tooth Design An involute gear design depends on two parameters the diametral pitch and the pressure angle. Oct 31, 2018 · Learn more about the different manufacturing processes for cutting involute gears in this article. The region of involute profile between these start and end points is termed the active profile. This becomes clear when the tooth flanks of the gears with different profile shifts are placed on top of each other. D = diameter of the circle Oct 31, 2018 · All profile shifted gears use the same involute for the tooth shape compared to their corresponding standard gears. (2) Step 3: Internal and external splines. Involute Spline is a spline having teeth with involute profiles. 25 times the module, is called a full depth tooth. 1. from publication: Research on the design of skiving tool for machining involute gears | Although the power skiving Download scientific diagram | Asymmetric involute spur gear tooth profile. For the purpose of defining a gear type, we are generally interested only in the active segment of the basic cutter profile. Usu-ally of four profile traces Download scientific diagram | Teeth profiles of spherical involute gear with from publication: The spherical involute bevel gear: Its geometry, kinematic behavior and standardization | Bevel gear Nov 5, 2023 · The axial section tooth profile of the offset involute cylindrical worm is illustrated in the left figure of Fig. Part of KHK's Gear Technical Reference for machine designers. Gears of this 'type satisfy all the requirements for smonthvaccurete and continuous motion. Gear Tooth Profile / One of the most popular tooth profiles is the Involute Tooth Profile. The Cartesian coordinates of a point on the involute are given at eqn 1. A gear wheel can be fully defined with as few as two parameters: the number of teeth ( z ) and module ( m ). Pitch rises, face width rises 2. Unlike the diagram for external gears, this diagram is plotted from tip to root, but also in the direction of increasing length of roll. The circular pitch is the distance measured on the circumference of the pitch circle from a point of one tooth to the corresponding point on the next tooth. As for teeth of helical gears, spiral bevel gears and racks, the twist direction of gears should be opposite to each other to mesh. 2. This profile has the very important property of maintaining a constant speed ratio between the two gears. Oct 31, 2018 · This also means that the transmission ratio of involute gears is independent of the center distance (for example, this is not the case with cycloidal gears). 10 (D) shows that part of the gear sulting gear involute produced. 7. l - Diagram. [20]. it is essential that the fun-damental properties of the involute ClUVebe clearly understood. The teeth are simply thinner at the back than at the front or cutting face. (Figure 4-6) Dec 31, 2020 · Step 2: Involute in gears and splines In splines or spur gears, a fraction of the profiles is an involute of a circle. Involute (Profile) Variation - The total amount of profile variation, plus to minus. Download scientific diagram | Usual modifications of involute helical gears. In Fig. Illustrating That the Involute May 1, 2019 · Profile and helix measurement belong to the elemental measurement of gears. 15, where the diagram obtained by GEAR PRO is drawn to the left and the diagram created in Microsoft Excel to the right (the orientation of the diagrams is in accordance with the orientation in the measurement protocol), it can be said that both methods lead to the same results. All deviations - whether of profile, helix or pitch - are calculated in involute coordinates, as these provide many advantages compared to Cartesian coordinates. line that forms the tooth profile below the Pitch Point and the arc that forms the tooth profile above the pitch point. 5. 1- Diagram Illustrating That the Gear Shaper Employs the "Molding-Generating" Process for Cutting Gears. 1 shows the tooth profile of a gear rack, which is the standard involute gear profile. The value of the involute generating parameter \( \theta \) starts at \( 0 \) on the base circle and ends at value, \( \theta_a \), which may be calculated the schematic diagram shown in Fig. Mar 8, 2023 · The face and flank of involute teeth are generated by a single curve as shown in the Involute Gear Profile. 1. (3), which is similar to the relation motion of involute gear profile inspection. 0 NOTE 1 : The subscripts 1 and 2 of z 1 and z 2 denote pinion and gear. sulting gear involute produced. The use of involute toothing is due on the one hand to the favorable meshing (engagement of two gearwheels). B-I_][-4-The common normal of involute gear teeth is a straight IineAB'. S-shaped gear adopts a progressive curved contact path, applying a concave and convex contact at the beginning and end of engagement. docx Author: e359848 Created Date: 7/6/2010 9:13:31 AM One of the fundamental s of gear design is the profile of the gear tooth. Take note of the following diagram, which is basically a zoom-in of the previous: Note the pitch point on the involute curve, and take note of the angle $\theta_P$ that occurs between the radial lines passing through the base and pitch points. One Shaft to Another, 38 Gear Technology /\ 8 Fig. Methods to The involute gear profile starts at the base circle and ends where the involute meets the tip circle, also known as the addendum circle. g. Download scientific diagram | Tooth profile of involute gear and novel HCR gear: (a) pinion tooth and (b) internal gear tooth. • Involute gear produces lesser noise than cycloidal gears The following online calculator computes the basic dimensions and tooth profile of an involute gear based on its module, number of teeth and pressure angle (the latter is usually 20°). They can be external or internal. For this reason – and because of the relatively simple manufacturing process – involute gears are mainly used in mechanical engineering. At PairGears, we are committed to delivering high-quality gear solutions tailored to meet the specific needs of our 38 Gear Technology Fig. Involute. Learn about the intersection of two circles and gear engineering concepts. 1] It consists of a disc whose diameter must be equal to the base circle diameter of the gear under test. The involute curve may be described as the curve generated by the end of a string that isunwrapped from a cylinder. 2 as follows: The involute gear profile starts at the base circle and ends where the involute meets the tip circle, also known as the addendum circle. Figure: Comparison of tooth flanks of profile-shifted gears Oct 31, 2018 · Involute function. Step 55: 55) We are now almost ready, but the first gear is fixed and can’t turn. There are other types of gear profiles, but they are mainly utilized in specialty applications such as cycloidal gears in clocks and watches. The involute profile is the path traced by a point on a line as the line rolls without slipping on the circumference of a circle. gear, rotates without slip with a mating involute body. Involute gears offer excellent efficiency and durability, while cycloidal gears provide compact designs and higher load capacities. With over 4,000 licenses sold worldwide, its functionality is dedicated to gear manufacturing and gear inspection and makes it easier for engineers—in the areas of calculation, manufacturing, and quality assurance—to collaborate and exchange data. Meshing of Involute Gears. Important terminologies in this figure : Tangent; Root circle; Base circle; Reference circle; Drive gear; Driven gear; Rotational sequence of the gears : P1 -> P2 -> P3 line that forms the tooth profile below the Pitch Point and the arc that forms the tooth profile above the pitch point. of the gear addendum. High hob teeth will produce low flats or hollows on the gear profile. This provides assembly flexibility. The popularity of the involute tooth profile is derived from many of it’s advantages, such as simplicity in design and ease of use. Today nearly every gear tooth uses an involute profile . a) profile slope, b) profile crowning, c) tip and root relief, d) lead slope, e) lead crowning, f) end reliefs (source shown in Figure 2. Download scientific diagram | Involute spur gear example. The pressure angle is the angle between the line of action and the normal line of centers. 2. The profile deviations of flank-1 and flank-3 are measured first. coordinate measuring machines (CMM) or traditional mechanical gear measuring machines [1] or by portable measuring machines such as laser tracker [2] or articulated arm CMM. The value of the involute generating parameter \( θ \) starts at \( 0 \) on the base circle and ends at value, \( θ_a \), which may be calculated the schematic diagram shown in Fig. Numbers 2-4 show the same hob mounted incor-rectly, with the resulting effect on the hob's lead chart (checked as mounted) and on the involute form produc d on the gear. The majority of gears used in industrial machinery are gears with an involute tooth profile. Gears have many The diagram of the traditional involute gear manufacturing by rack is shown in Fig. Involute gears When you read about designing gears, you are almost always reading about ‘involute’ gears. 0. These curves provide great flexibility in designing as well as manipulation [16, 17]. It is denoted by Pc. The involute can be described as that curve traced by a point ana crossed belt as it moves from one pulley to the other without slipp<lge. 2, we can represent the force on the tooth at any point along the path of con Dec 29, 2023 · The base circle of involute gear is the circle from which involute tooth profiles are determined. And the root segment of the basic cutter is used to define the root segment of a tool that can be used to cut the gear. As a hob cuts a gear, the top of the gear's involute form is finish cut at a dif-ferent point in time than the bottom. Go slowly and make sure that you follow each step carefully, and soon you’ll have a great gear ready for Jan 1, 2015 · A simple example: A pitch angle of 24° and a contact ratio of 1. Learn about basic racks and their significance to manufacturing of cylindrical involute gears. In addition it let you compose full gear layouts with connetcted gears to design multiple gears system with control of the input/output ratio and rotation speed. Involute gears are often manufactured by hobbing. At this time, α = (90 • + θ LR /2)π/180 • , and the profile slope deviations are corrected to 0. 0 Tips and Tricks Page 6 COPYRIGHT 2008 CADQUEST INC. Number of CS teeth equal to 60 teeth. 1-4). Download scientific diagram | 4: Involute tooth profile for harmonic drive teeth. 4. The equations for the involute Sep 7, 2022 · The coordinates ϕ b, r and z describe the 3D location of the individual point on an involute gear flank. A basic rack defines the tooth profile of a gear with infinite diameter and forms the basis of a family of gears. 3. 17 and 18 below) This property is critical in gear trains where the speed and torque ratios between gears must be precisely controlled. . This type of full depth tooth is most common, but The diagram thus drawn is the involute tooth profile. flutes will not produce the correct involute form, The hob win have high and low teeth which will produce unequal generating flats on the gear teeth . Tooth Loading Characteristics on True-Involute Spur Gears When spur gears mesh, contact is made by one pai(\] and two pairs of teeth alternately. Measuring involute gears on CMMs presents us with two special challenges. External in the shaft and internal in the hub. By making the tooth thickness of involute gears thicker or thinner, you can change gear strength and the center distance of paired gears. The curve is generated by a tool called an involute gear cutter, which cuts the gear teeth from a gear blank. Apr 22, 2022 · KISSsoft is a well-known software system that addresses gear manufacturing as a holistic process. The internal spline has to be manufactured with shaping or broaching, using an involute cut-ting tooth profile. We use the word involute because the contour of gear teeth curves inward. ) The circumference of the Jun 22, 2024 · This work involves synthetic curves to design new tooth profile for gears. Pc = πd/T. Any two involute gears can mesh regardless of the number of teeth if they have the same diametral pitch and pressure angle. It is possible to select the number the pinion teeth, the pressure angle and the tooth slope. The figure below shows the involute belonging to the base circle with the radius r b. Thus close tolerances between shaft locations are not required when using the involute profile. This design ensures that the point of contact between the gear teeth moves along a smooth curve, resulting in a constant angular velocity. That is, a gear's profile does not depend on the gear it mates with. It is well known that this tooth profile is an involute of a circle. It is particularly useful for defining the During the mesh cycle of a helical gear pair, the involute tooth profiles have a starting point and ending point. 17 and 18 below) The involute gear profile, sometimes credited to Leonhard Euler, [1] was a fundamental advance in machine design, since unlike with other gear systems, the tooth profile of an involute gear depends only on the number of teeth on the gear, pressure angle, and pitch. A basic rack is merely a set of geometric properties for describing gear tooth proportions. In gear systems, this profile provides specific advantages that make it ideal for high-efficiency power transmission. 13–7b, two gear blanks with fixed centers at O1 and O2 are shown having base circles whose respective radii are O1a and O2b. For the calculation of involute gears, the involute tooth flank must first be described mathematically. the involute is generated is called the base circle. Aug 13, 2023 · The base circle and pitch circle are important geometric dimensions of gears. maip fuusk cdxz eaua untq sutsfs kiwd bwnelm kcfjbh gvnzwgf