Drum brake pad thickness testing fixture

Abstract

The invention discloses a drum brake pad thickness testing fixture, which comprises a base, the top surface of which is provided with a mounting arm along the vertical direction; the balancing weight is connected to the side face of the mounting arm in a sliding mode, the balancing weight slides in the vertical direction, and a detection rod is arranged on the bottom face of the balancing weight in the vertical direction; the grating ruler is installed on the side face of the installation arm in the vertical direction, and a grating reading head of the grating ruler is fixedly connected with the balancing weight; the detection table is detachably mounted on the top surface of the base, the shape of the top surface of the detection table is matched with the shape of the bottom surface of the brake pad, and the detection rod is located above the detection table; according to the brake pad thickness detection device, the detection rod is pressed against the brake pad through the self weight of the balancing weight, the detection rod and other components, the thickness detection of the detection point position of the brake pad is achieved in cooperation with the grating ruler, and errors caused by different force applied to the brake pad in the detection process can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of drum brake pad detection, in particular to a drum brake pad thickness detection tool. Background Art

[0002] Drum brake pads generally include a base layer, an adhesive heat-insulating layer and a friction layer. The base layer and the friction layer are bonded together by the adhesive heat-insulating layer. The base layer is generally a steel plate. There are also several pairs of positioning holes on the brake pads. The positioning holes are generally arranged in two rows, with four pairs in each row. The aperture of the base layer hole in each positioning hole is smaller than the aperture of the friction layer hole. Brake pads usually have unequal thicknesses. When processing brake pads, the brake pad blank must first be subjected to inner arc grinding, drilling and other processing procedures, and finally it is ground on the outer arc surface to meet the thickness requirements of the brake shoe assembly drawing of the brake.

[0003] After the brake pad is processed, its thickness needs to be tested at multiple points to determine whether it meets the design requirements. Generally, the thickness at multiple pairs of positioning holes is tested. Traditional testing generally uses vernier calipers and micrometers. When using vernier calipers, micrometers and other measuring instruments to measure the thickness of the brake pad, the inside and outside of the drum brake pad are arcs, and the points on the two arc surfaces are different, resulting in measurement errors. The traditional caliper is not accurately positioned, and the force used is different. The measurement error is as high as 0.06-0.10mm.

[0004] A Chinese utility model patent with publication number CN219455034U discloses a shoe brake pad thickness detection device, including an operating table and an operating box, as well as a first measuring rod in a horizontal state and sliding vertically with the operating table, a pair of support rods symmetrically distributed in the horizontal direction about the first measuring rod and parallel to the first measuring rod, a vertical moving mechanism, a connecting plate that can move vertically, a second measuring rod fixedly connected to the lower surface of the connecting plate and located directly above the first measuring rod and parallel to the first measuring rod, and a measuring mechanism for measuring the lifting height of the first measuring rod. When the first measuring rod is at the highest point, it is flush with the support rod, and the cross-sections of the support rod, the first measuring rod and the second measuring rod are all circular.

[0005] This brake pad thickness detection device is difficult to control the downforce, which will affect the detection accuracy. Summary of the invention

[0006] The object of the present invention is to provide a drum brake pad thickness gauge to solve at least one of the above technical problems.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A drum brake pad thickness gauge, comprising:

[0009] A base, wherein a mounting arm is provided on the top surface of the base in a vertical direction;

[0010] A counterweight block is slidably connected to the side of the mounting arm, the counterweight block slides in a vertical direction, and a detection rod is provided on the bottom surface of the counterweight block in a vertical direction;

[0011] A grating ruler is installed on the side of the mounting arm along the vertical direction, and the grating reading head of the grating ruler is fixedly connected to the counterweight block;

[0012] A detection platform is detachably mounted on the top surface of the base, the top surface shape of the detection platform matches the shape of the bottom surface of the brake pad, and the detection rod is located above the detection platform.

[0013] The present invention provides a base and a mounting arm for installing a counterweight and a grating ruler, and provides a detection platform for placing brake pads. The counterweight is set to slide up and down so that the counterweight can drive a detection rod and a grating reading head of the grating ruler to slide up and down. The deadweight of components such as the counterweight and the detection rod is utilized to press the detection rod against the brake pad, and the brake pad is pressed against the detection platform, and the grating ruler is cooperated to realize thickness detection of detection points of the brake pad. The force applied by the detection rod to the detection points of the brake pad is only the deadweight of components such as the counterweight and the detection rod. The magnitude of the force exerted by the detection rod on different detection points and different brake pads is consistent, and the error caused by the different magnitudes of the force applied to the brake pad during detection can be effectively reduced.

[0014] Specifically, a slide rail is provided on the side of the mounting arm in the vertical direction, and a slider is slidably connected to the slide rail. The slider is fixed to the counterweight block, and the counterweight block is slidably installed on the mounting arm through the cooperation of the set slide rail and the slider, so that the counterweight block can slide up and down along the slide rail.

[0015] Furthermore, an operating rod is provided above the counterweight block, one end of the operating rod is rotatably connected to the top of the mounting arm, the operating rod is connected to the counterweight block through a connecting rod, a through slot is opened on the side of the operating rod, the slotting direction of the through slot is consistent with the length direction of the operating rod, a latch is slidably installed in the through slot, the latch is rotatably connected to one end of the connecting rod, and the other end of the connecting rod is rotatably connected to the top surface of the counterweight block. Both ends of the latch are provided with a first stopper, and through the cooperation of the set operating rod and the connecting rod, lifting the operating rod away from the end of the mounting arm can drive the connecting rod to rise, and then drive the counterweight block to rise, so that the brake pad is placed on the testing platform, and the testing is more convenient; through the set latch, one end of the connecting rod can slide along the through slot, and can also rotate with the latch as the axis, so that the counterweight block can be driven to slide up and down through the connecting rod, and the set first stopper is used to block the connecting rod and the operating rod to prevent the latch from detaching from the through slot and the connecting rod.

[0016] Furthermore, a pair of positioning pins cooperating with the positioning holes of the brake pad are provided on the top surface of the detection platform in the vertical direction. The positioning pins cooperate with the positioning holes on the brake pad to achieve positioning of the brake pad, making the detection position more accurate and reducing the error caused by the deviation of the detection point.

[0017] Furthermore, a horizontally arranged mounting plate is fixed to the side of the mounting arm, and two fixing posts arranged in the vertical direction are slidably connected to the mounting plate, and the fixing post slides in the vertical direction. A compression spring is sleeved on the fixing post, and a retaining ring is provided on the fixing post. One end of the compression spring abuts against the retaining ring, and the other end abuts against the bottom surface of the mounting plate. The outer diameter of the fixing post is larger than the aperture of the hole body of the base layer of the brake pad and smaller than the aperture of the hole body of the friction layer of the brake pad. The two fixing posts extend into the holes of a pair of brake pad friction layers and press against the base layer of the brake pad; the mounting plate is provided for installing the fixing post, and the fixing post is between the compression spring and the retaining ring The ring is pressed against the base layer of the brake pad with the cooperation of the lower ring, so that the lower arc surface of the brake pad fits with the top surface of the test bench, and the brake pad is fixed on the test bench, which makes the detection more convenient and can improve the positioning accuracy of the locating pin, thereby improving the accuracy of the brake pad thickness detection; the detection point is located in the middle of a pair of locating holes. If the fixing column is directly pressed against the upper surface of the brake pad, it is easy to cause a slight deformation of the upper surface of the brake pad, thereby affecting the detection result. The fixing column is extended into the hole body of the brake pad friction layer and pressed against the base layer of the brake pad. The base layer is generally a steel plate, which is difficult to deform, and pressing against the base layer will not affect the friction layer on the base layer, which can reduce the detection error.

[0018] Furthermore, the bottom end of the fixing column is concave to form a receiving groove for receiving the top of the positioning pin, so as to avoid position conflict between the fixing column and the positioning pin.

[0019] Furthermore, a second stopper is provided at the top end of the fixing column, and the second stopper is located above the mounting plate to prevent the fixing column from being separated from the mounting plate.

[0020] Furthermore, a connecting plate is provided between the second stopper and the mounting plate, and a pair of the fixing columns are both passed through the connecting plate and are slidably connected to the connecting plate. Lifting the connecting plate can drive both fixing columns to rise, thereby facilitating fixing of the brake pad.

[0021] Furthermore, the connecting plate is connected to the counterweight by a rope. When the detection rod is pressed against the brake pad, the rope is in a relaxed state, and the counterweight can be driven up by lifting the operating rod, thereby driving the connecting plate up and the fixing column up as well, thereby facilitating the fixing of the brake.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention provides a base and a mounting arm for installing a counterweight and a grating ruler, and provides a detection platform for placing brake pads. The counterweight is set to slide up and down so that the counterweight can drive the detection rod and the grating reading head of the grating ruler to slide up and down. The deadweight of the counterweight, the detection rod and other components are used to press the detection rod against the brake pad, and the brake pad is pressed against the detection platform. In conjunction with the grating ruler, the thickness of the brake pad detection point is detected. The force applied by the detection rod to the brake pad detection point is only the deadweight of the counterweight, the detection rod and other components. The magnitude of the force applied by the detection rod to different detection points and different brake pads is consistent, which can effectively reduce the error caused by the different magnitudes of the force applied to the brake pad during detection.

[0024] (2) The present invention provides a positioning pin for positioning the brake pad, which can improve the accuracy of thickness detection.

[0025] (3) The present invention provides a mounting plate for installing a fixing column, which is pressed against the base layer of the brake pad with the cooperation of a compression spring and a retaining ring, so that the lower arc surface of the brake pad fits with the top surface of the test bench, and the brake pad is fixed on the test bench, making the test more convenient and improving the positioning accuracy of the positioning pin, thereby improving the accuracy of the brake pad thickness test. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front view of a drum brake pad thickness gauge in this embodiment;

[0027] Figure 2 It is a side view of a drum brake pad thickness gauge in this embodiment;

[0028] Figure 3 This is a diagram showing the position relationship between the fixing column and the positioning pin in this embodiment;

[0029] In the figure: 1. base; 2. mounting arm; 3. counterweight; 4. detection rod; 5. grating ruler; 501. scale grating; 502. grating reading head; 6. display screen; 7. mounting table; 8. detection table; 9. slide rail; 10. slider; 11. operating lever; 12. connecting rod; 13. through groove; 14. latch; 15. first stopper; 16. brake pad; 161. base layer; 162. friction layer; 17. positioning hole; 171. first positioning hole; 172. second positioning hole; 18. positioning pin; 19. mounting plate; 20. fixing column; 21. compression spring; 22. retaining ring; 23. receiving groove; 24. second stopper; 25. connecting plate; 26. rope. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 and Figure 2 As shown, this embodiment provides a drum brake pad thickness gauge, comprising: a base 1, a mounting arm 2, a counterweight 3, a detection rod 4, a grating ruler 5 and a detection platform 8.

[0032] A mounting arm 2 is provided on the top surface of the base 1 in the vertical direction, a slide rail 9 is provided on the side surface of the mounting arm 2 in the vertical direction, a slider 10 is slidably connected to the slide rail 9, the slider 10 is fixed to the counterweight 3, and the counterweight 3 is slidably mounted on the mounting arm 2 by cooperating with the provided slide rail 9 and the slider 10, so that the counterweight 3 can slide up and down along the slide rail 9, and a detection rod 4 is provided on the bottom surface of the counterweight 3 in the vertical direction; an operating rod 11 is provided above the counterweight 3, one end of the operating rod 11 is rotatably connected to the top end of the mounting arm 2, the operating rod 11 is connected to the counterweight 3 through a connecting rod 12, a through slot 13 is provided on the side surface of the operating rod 11, the slotting direction of the through slot 13 is consistent with the length direction of the operating rod 11, a latch 14 is slidably installed in the through slot 13, and the latch 14 It is rotatably connected to one end of the connecting rod 12, and the other end of the connecting rod 12 is rotatably connected to the top surface of the counterweight 3. First blocks 15 are provided at both ends of the pin 14. The operating rod 11 is arranged to cooperate with the connecting rod 12. Lifting the operating rod 11 away from the end of the mounting arm 2 can drive the connecting rod 12 to rise, and then drive the counterweight 3 to rise, so that the brake pad 16 can be placed on the testing table 8, which makes the testing more convenient. The pin 14 is arranged so that one end of the connecting rod 12 can slide along the through groove 13, and can also rotate with the pin 14 as the axis, so that the counterweight 3 can be driven up and down by the connecting rod 12. The first block 15 is used to block the connecting rod 12 and the operating rod 11 to prevent the pin 14 from escaping from the through groove 13 and the connecting rod 12. A grating ruler 5 is installed on the side of the mounting arm 2 along the vertical direction. The grating ruler 5 includes a scale grating 501 and a grating reading head 502 slidably connected to the scale grating 501. The scale grating 501 is installed on the side of the mounting arm 2 along the vertical direction. The grating reading head 502 is fixedly connected to the counterweight block 3. The counterweight block 3 is provided with a display screen 6. The display screen 6 is electrically connected to the grating ruler 5 for observing and reading detection data. A mounting platform 7 is installed on the base 1. A detection platform 8 is detachably installed on the mounting platform 7 by bolts. The top surface of the detection platform 8 is an arc surface, which matches the shape of the bottom surface of the brake pad 16. The detection rod 4 is located above the detection platform 8.

[0033] The present invention provides a base 1 and a mounting arm 2 for installing a counterweight 3 and a grating ruler 5, and provides a detection platform 8 for placing a brake pad 16. The counterweight 3 is set to slide up and down so that the counterweight 3 can drive a detection rod 4 and a grating reading head 502 of the grating ruler 5 to slide up and down. The deadweight of the counterweight 3, the detection rod 4 and other components is utilized to press the detection rod 4 against the brake pad 16, and the brake pad 16 is pressed against the detection platform 8, and the grating ruler 5 is cooperated to realize the thickness detection of the detection point of the brake pad 16. The force applied by the detection rod 4 to the detection point of the brake pad 16 is only the deadweight of the counterweight 3, the detection rod 4 and other components. The magnitude of the force applied by the detection rod 4 to different detection points and different brake pads 16 is consistent, which can effectively reduce the error caused by the different magnitudes of the force applied to the brake pad 16 during detection.

[0034] Furthermore, in the prior art, the brake pad 16 includes a base layer 161 and a friction layer 162 bonded to the top surface of the base layer 161. The brake pad 16 is provided with a plurality of pairs of positioning holes 17. In each positioning hole 17, the aperture of the base layer 161 is smaller than the aperture of the friction layer 162. The base layer 161 aperture is defined as a first positioning hole 171, and the friction layer 162 aperture is defined as a second positioning hole 172. That is, the base layer 161 is provided with a first positioning hole 171 as a part of the positioning hole 17, and the friction layer 162 is provided with a second positioning hole 172 as a part of the positioning hole 17. The first positioning hole 171 and the second positioning hole 172 are coaxially arranged, and the diameter of the first positioning hole 171 is smaller than the diameter of the second positioning hole 172. The diameter of the second positioning hole 172; the present invention is provided with a pair of positioning pins 18 cooperating with the first positioning hole 171 on the top surface of the detection platform 8 in the vertical direction, and the positioning pins 18 are provided to cooperate with the positioning holes 17 provided on the brake pad 16 to realize the positioning of the brake pad 16, so that the detection position is more accurate and the error caused by the deviation of the detection point can be reduced; a horizontally arranged mounting plate 19 is fixed to the side of the mounting arm 2, and two fixing columns 20 arranged in the vertical direction are slidably connected to the mounting plate 19, and the fixing column 20 slides in the vertical direction. A second stopper 24 is provided on the top of the fixing column 20, and the second stopper 24 is located above the mounting plate 19 to prevent the fixing column 20 from detaching from the mounting plate 19; the second stopper 24 and the mounting plate A connecting plate 25 is provided between the mounting plate 19, a pair of fixed columns 20 are both penetrated by the connecting plate 25 and are slidably connected to the connecting plate 25, and a clearance hole for the detection rod 4 to pass through is opened on the mounting plate 19 and the connecting plate 25, and lifting the connecting plate 25 can drive both fixed columns 20 to rise; the connecting plate 25 is connected to the counterweight block 3 by a rope 26, and when the detection rod 4 is pressed against the brake pad 16, the rope 26 is in a relaxed state, and can drive the counterweight block 3 to rise by lifting the operating rod 11, thereby driving the connecting plate 25 to rise, so that the fixed column 20 also rises; a compression spring 21 is sleeved on the fixed column 20, and a retaining ring 22 is provided on the fixed column 20, and one end of the compression spring 21 is in contact with the retaining ring 22 , and the other end abuts against the bottom surface of the mounting plate 19. The outer diameter of the fixing column 20 is larger than the aperture of the first positioning hole 171 and smaller than the aperture of the second positioning hole 172. The two fixing columns 20 extend into a pair of second positioning holes 172 and press against the base layer 161 of the brake pad 16. The mounting plate 19 is provided to install the fixing column 20. The fixing column 20 is pressed against the base layer 161 of the brake pad 16 under the cooperation of the compression spring 21 and the retaining ring 22, so that the lower arc surface of the brake pad 16 fits with the top surface of the detection platform 8, and the brake pad 16 is fixed on the detection platform 8, which makes the detection more convenient and can improve the positioning accuracy of the positioning pin 18, thereby improving the accuracy of the thickness detection of the brake pad 16; such as Figure 3As shown, the bottom end of the fixing column 20 is concave to form a receiving groove 23 for accommodating the top of the positioning pin 18, so as to avoid the position conflict between the fixing column 20 and the positioning pin 18; the detection point is located in the middle of a pair of positioning holes 17. If the fixing column 20 is directly pressed against the upper surface of the brake pad 16, it is easy to cause a slight deformation of the upper surface of the brake pad 16, thereby affecting the detection result. The fixing column 20 is extended into the second positioning hole 172 and pressed against the base layer 161. The base layer 161 is generally a steel plate and is difficult to deform. Pressing against the base layer 161 will not affect the friction layer 162 on the base layer 161, so the detection error can be reduced.

[0035] Working principle: when there is no brake pad 16 on the testing platform 8, the testing rod 4 is directly pressed against the testing platform 8, and the grating reading head 502 is in the initial position; lift the operating rod 11, the connecting rod 12 rises, driving the counterweight block 3 to rise, and further driving the testing rod 4 and the fixed column 20 to rise, aligning the brake pad 16 with the positioning pin 18 and placing it on the testing platform 8, lower the operating rod 11, and the fixed column 20 first fixes the brake pad 16, and continue to lower the operating rod 11 to make the testing rod 4 contact with the brake pad 16, and let go, so that the testing rod 4 is pressed against the brake pad 16 under the action of gravity. At this time, the distance between the position of the grating reading head 502 and the initial position is the thickness of the brake pad 16.

[0036] It should be noted that although the present invention is disclosed as above by specific embodiments, the above embodiments are not intended to limit the present invention. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A drum brake pad thickness gauge, characterized in that: include: A base, wherein a mounting arm is provided on the top surface of the base in a vertical direction; A counterweight block is slidably connected to the side of the mounting arm, the counterweight block slides in a vertical direction, and a detection rod is provided on the bottom surface of the counterweight block in a vertical direction; A grating ruler is installed on the side of the mounting arm along the vertical direction, and the grating reading head of the grating ruler is fixedly connected to the counterweight block; A detection platform is detachably mounted on the top surface of the base, the top surface shape of the detection platform matches the shape of the bottom surface of the brake pad, and the detection rod is located above the detection platform.

2. A drum brake pad thickness gauge according to claim 1, characterized in that: A slide rail is provided on the side surface of the mounting arm along the vertical direction, and a slider is slidably connected to the slide rail, and the slider is fixed to the counterweight block.

3. A drum brake pad thickness gauge according to claim 1, characterized in that: An operating rod is provided above the counterweight block, one end of the operating rod is rotatably connected to the top end of the mounting arm, the operating rod is connected to the counterweight block via a connecting rod, a through slot is provided on the side of the operating rod, the slotting direction of the through slot is consistent with the length direction of the operating rod, a latch is slidably installed in the through slot, the latch is rotatably connected to one end of the connecting rod, the other end of the connecting rod is rotatably connected to the top surface of the counterweight block, and first stops are provided at both ends of the latch.

4. A drum brake pad thickness gauge according to claim 1, characterized in that: A pair of positioning pins cooperating with the positioning holes of the brake pads are arranged on the top surface of the detection platform in the vertical direction.

5. A drum brake pad thickness gauge according to claim 4, characterized in that: A horizontally arranged mounting plate is fixed to the side of the mounting arm, and two fixing columns arranged in the vertical direction are slidably connected to the mounting plate. The fixing columns slide in the vertical direction, and a compression spring is sleeved on the fixing columns. A retaining ring is provided on the fixing columns, and one end of the compression spring abuts against the retaining ring, and the other end abuts against the bottom surface of the mounting plate. The outer diameter of the fixing columns is larger than the aperture of the hole body of the base layer of the brake pad and smaller than the aperture of the hole body of the friction layer of the brake pad. The two fixing columns extend into the holes of a pair of brake pad friction layers and press against the base layer of the brake pad.

6. A drum brake pad thickness gauge according to claim 5, characterized in that: The bottom end of the fixing column is concave to form a receiving groove for receiving the top of the positioning pin.

7. A drum brake pad thickness gauge according to claim 5, characterized in that: A second stopper is disposed at the top end of the fixing column, and the second stopper is located above the mounting plate.

8. A drum brake pad thickness gauge according to claim 7, characterized in that: A connecting plate is provided between the second stopper and the mounting plate, and a pair of the fixing columns are both passed through the connecting plate and are slidably connected to the connecting plate.

9. A drum brake pad thickness gauge according to claim 8, characterized in that: The connecting plate is connected to the counterweight block via a rope, and when the detection rod is pressed against the brake pad, the rope is in a relaxed state.

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