A measuring device and method for measuring valve stroke difference and valve bridge deformation

Abstract

The present invention relates to the technical field of monitoring the operating conditions of internal combustion engines, specifically a measuring device and method for measuring valve stroke differences and valve bridge deformation. The valve bridge guide post is fixed to a shaft as a whole, and the valve bridge guide post deformation caused by uneven valve force is calculated by calculating the rotation angle of the T-shaped pointer on the shaft; the parallel plate on the valve guide post is connected to the crankshaft set on the shaft through a crank-connecting rod mechanism, and the vertical reciprocating motion of the parallel plate is converted into reciprocating rotational motion of the crankshaft through the crank-connecting rod mechanism. The crankshaft drives the pointer bracket and the T-shaped pointer to perform reciprocating rotational motion as a whole, and the valve stroke difference is calculated. The present invention can achieve simultaneous measurement of valve bridge guide post deformation and valve stroke, and can also measure them separately. It is simple to disassemble and assemble, and the accuracy of the high-speed camera and the dial, as well as the size of each component of the device, can be selected according to actual conditions and needs.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engine operating condition monitoring, and in particular to a measuring device and a measuring method for measuring valve stroke difference and valve bridge deformation. Background Art

[0002] As a critical component of an internal combustion engine, the valve bridge assembly controls intake and exhaust volume during engine operation, ensuring proper function. When uneven force is applied to the valves, the valve bridge applies torque to the valve bridge guide pin during operation, causing deformation and abnormal valve travel. This prevents the engine from ideally performing intake and exhaust strokes, resulting in suboptimal combustion, low efficiency, and poor emissions. In severe cases, this can damage the valve bridge guide pin, rendering the engine inoperable. Therefore, measuring the valve bridge guide pin shape and valve travel is crucial.

[0003] The valves and valve bridges are wrapped by the cylinder head and valve cover. The valves and valve bridge guide pillars are small in size. The free end of the valve bridge guide pillar is wrapped by the valve bridge and the valve bridge moves quickly. The shape variables of the valve bridge guide pillar and the detailed valve stroke cannot be obtained by the naked eye. The shape variables of the valve bridge guide pillar and the valve stroke can only be obtained through the measuring equipment of the test bench, so as to judge the influence of uneven valve force on the deformation of the valve bridge guide pillar and the valve stroke.

[0004] A valve stroke measuring device (CN201955072U) invented a valve stroke measuring device, but the device did not take into account the vibration of the mounting bracket and the valve, and the loosening of the adjustment nut, which affected the measurement accuracy of the valve stroke; a universal detection device for engine valve lift (CN101963484A) invented a universal detection device for valve lift, which used parts such as reduction gears and micrometers, resulting in a large transmission error of the valve stroke, which increased the error of the detection results and made it impossible to perform continuous and accurate readings when the engine was running. Summary of the Invention

[0005] To address the above issues, the present invention aims to provide a device and method for measuring valve travel differences and valve bridge deformation. This device can continuously measure valve travel while the engine is running, enabling simultaneous measurement of valve bridge guide deformation and valve travel. It can also measure both independently, and is simple to assemble and disassemble. The technical solution is as follows:

[0006] A measuring device for measuring valve stroke difference and valve bridge deformation includes a valve bridge guide post fixing plane and a shaft; a valve bridge guide post, a first bearing seat, and a second bearing seat located in a straight line are fixedly arranged in sequence on the valve bridge guide post fixing plane; the valve bridge guide post is vertically arranged, and the suspended end at the top of the valve bridge cooperates with the guide hole of the valve bridge to enable the valve bridge to slide up and down along the valve bridge guide post; a shaft bracket is fixedly arranged at the bottom of the valve bridge guide post;

[0007] One end of the shaft is fixed in the shaft bracket, and the other end is passed through the bearings of the first bearing seat and the second bearing seat in sequence; a vertical dial bracket is fixed on the first bearing seat, and a dial is provided on the top of the dial bracket;

[0008] A third pointer bracket is fixedly provided on the shaft near the second bearing seat, and a third T-shaped pointer matching the height of the dial is fixedly provided on the top of the third pointer bracket;

[0009] It also includes a valve force transmission mechanism with the same structure vertically arranged on the left and right sides of the valve bridge guide column, and a first pointer bracket and a second pointer bracket arranged between the first bearing seat and the third pointer bracket;

[0010] The valve force transmission mechanism includes a vertically arranged valve guide and a valve spring sleeved on the valve guide. The bottom of the valve guide can be movably inserted into the fixed plane of the valve bridge guide. The top of the valve guide is fixedly provided with a valve spring seat and is located below the valve bridge. It moves downward with the pressure generated by the downward movement of the valve bridge. The bottom of the valve spring abuts against the fixed plane of the valve bridge guide, and the top is limited by the valve spring seat. When the valve bridge pressure is released, the valve guide is rebounded.

[0011] The valve spring seats of the two valve force transmission mechanisms are respectively fixed to one end of the first parallel plate and the second parallel plate. The other end of the first parallel plate is connected to the first crankshaft mounted on the shaft through a bearing sleeve through a first crank-connecting rod mechanism; the other end of the second parallel plate is connected to the second crankshaft mounted on the shaft through a bearing sleeve through a second crank-connecting rod mechanism.

[0012] The first crankshaft and the second crankshaft are fixedly connected to the bottom end of the first pointer bracket and the bottom of the second pointer bracket respectively; the tops of the first pointer bracket and the second pointer bracket are respectively provided with a first T-shaped pointer and a second T-shaped pointer that match the height of the dial;

[0013] It also includes a high-vibration-resistant high-speed camera arranged on one side of the second bearing seat for photographing scale changes of the first T-shaped pointer, the second T-shaped pointer and the third T-shaped pointer.

[0014] Furthermore, a vibration sensor bracket is provided on the fixed plane of the valve bridge guide column, and a vibration sensor is provided on the top of the vibration sensor bracket through a vibration sensor support block; the center of gravity height of the vibration sensor is consistent with the center of gravity height of the three T-shaped pointers, the center of gravity height of the dial, and the center of gravity height of the high-vibration-resistant high-speed camera.

[0015] Furthermore, the first crank-connecting rod mechanism includes a crank arm and a connecting rod, one end of the crank arm is fixedly connected to the first crankshaft, and the other end is fixedly connected to the connecting rod shaft, the connecting rod shaft is rotatably connected to the bottom end of the connecting rod through a connecting rod bearing; the top end of the connecting rod is rotatably connected to the connecting rod pin bracket through a connecting rod pin, and the connecting rod pin bracket is fixed to the bottom of the first parallel plate; the second crank-connecting rod mechanism has the same structure as the first crank-connecting rod mechanism.

[0016] Furthermore, the inner wall of the first crankshaft / the second crankshaft is sleeved on the outer ring of the bearing, and the inner ring of the bearing is mounted on the shaft through a expansion sleeve.

[0017] Furthermore, the high-vibration-resistant high-speed camera is arranged on a high-vibration-resistant high-speed camera bracket, and strong light sources are symmetrically provided on both sides thereof, and the two strong light sources are at the same height as the high-vibration-resistant high-speed camera.

[0018] A method for measuring valve bridge deformation using the above-mentioned measuring device for measuring valve stroke difference and valve bridge deformation comprises the following steps:

[0019] Step 1: Take a photo with a high-speed, vibration-resistant camera to record the scale line on the dial pointed by the third T-shaped pointer, and obtain the change value ΔX1 of the scale line pointed by the third T-shaped pointer through image recognition;

[0020] Step 2: Calculate the circumference of the circle with radius R1, which is the distance from the uppermost endpoint B of the scale line 0 to the center line of the shaft. Then, calculate the rotation angle of the third T-shaped pointer, which is the rotation angle θ of the shaft, and the rotation angle θ1 of the shaft bracket:

[0021]

[0022] Step 3: Based on the rotation angle θ1 of the shaft bracket and the distance r1 between the fixed point A (i.e., the fixed point near the suspended end) on the valve bridge guide column and the upper edge of the shaft bracket and the shaft centerline, the deformation trajectory circle of the valve bridge guide column near the fixed end is obtained; the deformation of the valve bridge guide column caused by uneven valve force is obtained as:

[0023]

[0024] Furthermore, the step 1 is specifically as follows:

[0025] Make four marking points on the dial, perform marking point recognition on the four marking points, set the marking point acquisition frequency of the image recognition pair and the vibration sensor acquisition frequency to the same frequency, obtain the motion law of the four marking points, and calculate the average of the motion law of the four marking points to obtain the vibration law of the dial; calculate the average of the obtained vibration law of the dial and the vibration data obtained by the vibration sensor to obtain the vibration data of the entire measurement system; color the fingertip of the third T-type pointer, obtain the data of the scale line pointed by the third T-type pointer in the photo through image recognition and high-vibration-resistant high-speed camera, and then subtract the vibration data of the test system to eliminate the influence of vibration and obtain the accurate scale change value ΔX1 of the third T-type pointer.

[0026] A method for measuring valve stroke difference using the above-mentioned measuring device for measuring valve stroke difference and valve bridge deformation comprises the following steps:

[0027] Step a: taking photos with a high-speed, vibration-resistant camera to record the scale line on the dial pointed by the first T-shaped pointer, and obtaining a change value ΔX2 of the scale line pointed by the first T-shaped pointer through image recognition;

[0028] Step b: Calculate the circumference of a circle with a radius R1, which is the distance from the uppermost endpoint B of the scale line 0 to the centerline of the shaft. Calculate the rotation angle θ2 of the first T-shaped pointer, which is the rotation angle θ2 of the first crankshaft, which is the rotation angle θ2 of the connecting rod shaft:

[0029]

[0030] Step c: Define the axis centerline as l1. The intersection of the crank arm motion plane and the axis centerline l1 is inside the first crankshaft and is defined as point O. The connecting rod pin centerline is l2, and the connecting rod shaft centerline is l3. The connecting rod motion plane intersects the connecting rod pin centerline l2 at point D, and the connecting rod shaft centerline l3 at point E. Draw a perpendicular line from point D to the first parallel plate to obtain the foot of the perpendicular, which is point C.

[0031] Define the connecting rod pin centerline after the valve guide is displaced as l'2, and the connecting rod shaft centerline as l'3; the corresponding points D and E change to points D' and E' respectively;

[0032] Then DD′ represents the displacement of the parallel plate, that is, the displacement of the valve guide; EE′ represents the displacement of the connecting rod shaft before and after the valve guide is displaced; the intersection of the extended line of CD and OE′ is point FF;

[0033] Based on the rotation angle θ2 of the first crankshaft, the angle ∠OEF between the crank arm and the connecting rod during initial installation, the distance r2 from the connecting rod shaft center to the first crankshaft center, the distance DE between the centerlines of the connecting rod ends, and the straight-line distance EE′ between the centerlines of the lower end of the connecting rod before and after the valve guide is displaced, the distance D′E between the centerline of the upper end of the connecting rod after the valve guide is displaced and the centerline of the lower end of the connecting rod before and after the valve guide is displaced is calculated as:

[0034]

[0035] horn and bring in Then the valve stroke ΔS1 at the first parallel plate is:

[0036]

[0037] Step d: Similarly, the stroke ΔS2 of the valve at the second parallel plate is:

[0038] ΔS2=DE-D″E

[0039]

[0040] Step e: Due to the uneven force on the valve, the difference in valve stroke on the left and right sides is:

[0041]

[0042] Furthermore, the step a is specifically as follows:

[0043] Four marking points are made on the dial, and the four marking points are recognized. The marking point acquisition frequency of the image recognition pair and the vibration sensor acquisition frequency are set to the same frequency to obtain the motion law of the four marking points. The motion law of the four marking points is averaged to obtain the vibration law of the dial; the obtained vibration law of the dial and the vibration data obtained by the vibration sensor are averaged to obtain the vibration data of the entire measurement system, the fingertips of the first T-type pointer and the fingertips of the second T-type pointer are colored with different colors, and the data of the scale line pointed by the T-type pointer in the photo is obtained by an image recognition high-vibration-resistant high-speed camera, and then the vibration data of the test system is subtracted to eliminate the influence of vibration and obtain accurate scale change values ​​ΔX2 and ΔX3 pointed by the first T-type pointer and the second T-type pointer.

[0044] The beneficial effects of the present invention are:

[0045] This invention addresses the vibration issues associated with the measuring device and valves, reducing the impact of vibration on measurement accuracy. This allows for continuous valve stroke measurement while the engine is running, reflecting whether the valves on both sides of the valve bridge are evenly stressed. Currently, there are very few devices for measuring the deformation of engine valve bridge guide pins. The moving parts involved in measuring valve stroke and valve bridge guide pin deformation in this invention are in direct contact, resulting in negligible transmission errors. This allows for simultaneous or independent measurement of valve bridge guide pin deformation and valve stroke, and simple assembly and disassembly. The accuracy of the high-speed camera and dial, as well as the dimensions of the device's components, can be selected based on actual conditions and requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the measuring device for measuring valve stroke difference and valve bridge deformation.

[0047] Figure 2 This is a diagram of the crank-connecting rod arrangement.

[0048] Figure 3 A top view of the measuring device.

[0049] Figure 4 This is a schematic diagram of the dial marking points.

[0050] Figure 5 It is a local picture.

[0051] Figure 6 This is the measurement principle diagram.

[0052] In the figure: 1-valve bridge guide pillar fixing plane; 2-vibration sensor bracket; 3-shaft bracket; 4-valve bridge guide pillar; 5-valve spring; 6-valve guide pillar; 7-valve spring seat; 8-locking plate; 9-first parallel plate; 10-vibration sensor support block; 11-vibration sensor; 12-valve bridge; 13-first bearing seat; 14-dial bracket; 15-dial; 16-first crank-connecting rod mechanism; 17-first T-type pointer; 18-second parallel plate; 19-second T-type pointer; 20-second crank-connecting rod mechanism; 21-third T-type pointer; 22-third pointer bracket; 23-expansion sleeve a; 24-bearing a; 25-shaft; 26-high-vibration-resistant high-speed camera; 27-strong light source; 28-high-vibration-resistant high-speed camera bracket; 29-second bearing seat; 30-second pointer bracket; 31-second crankshaft; 32-bearing b; 33-expansion sleeve b; 34-expansion sleeve c; 35-bearing c; 36-first pointer bracket; 37-first crankshaft; 38-bearing d; 39-expansion sleeve d; 40-second crank arm; 41-first crank arm; 1-1—crank; 1-2—connecting rod shaft; 1-3—connecting rod; 1-4—connecting rod pin; 1-5—connecting rod pin bracket; 1-6—connecting rod bearing. DETAILED DESCRIPTION

[0053] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] like Figure 1 As shown, the measuring device includes: a bearing, a bearing seat, a shaft, a shaft bracket, a T-shaped pointer, a pointer bracket, a dial, a dial bracket, a crankshaft, a connecting rod, a connecting rod pin, a parallel plate, a connecting rod pin bracket, a vibration sensor, a vibration sensor support bracket, a vibration sensor support block, a high-vibration-resistant high-speed camera, a high-vibration-resistant high-speed camera bracket, a valve bridge guide column, a valve bridge guide column fixing plane, a valve spring, a valve guide column, a valve spring seat, and a locking plate.

[0055] Specifically, the test device is installed at Figure 1 The measurement device diagram shown in Figure 2 The crank-connecting rod device shown in the figure, Figure 3 The top view shown, Figure 4 The scale mark points shown, Figure 5 The partial diagram and Figure 6 The schematic diagram is shown. The motion trajectory of the valve is the same as that of the valve guide, so only the valve guide is shown in the above figure. The two valve springs in the device are symmetrical about the mid-vertical line of the valve bridge. Figure 1 The valve spring shown in the figure is the right valve spring. The installation position and movement state of the left valve spring, valve bridge and valve guide are the same as those on the right.

[0056] One end of the valve bridge guide post 4 is fixed to the valve bridge guide post fixing plane 1, while the other end is suspended. The suspended end engages with a guide hole in the valve bridge 12, allowing the valve bridge to slide up and down along the suspended end. The valve spring 5 is vertically mounted along the valve guide post 6, secured by the valve spring seat 7 and the locking plate 8. The valve guide post 6 contacts the valve bridge 12. When the valve bridge 12 is subjected to a downward force, the valve bridge 12 presses the valve guide post 6 downward. The valve guide post 6 presses the valve spring seat 7, compressing the valve spring along the valve guide post 6 and causing the valve bridge 12 to move downward along the valve bridge guide post 4. When the valve bridge 12 is no longer under force, the compressed valve spring 5 rebounds along the valve guide post 6, and the valve bridge 12, under the elastic force of the valve spring, moves upward along the valve bridge guide post 4. Throughout this movement, the motion trajectory of the valve spring seat matches the travel of the valve guide post.

[0057] 1. Measure the variable part of the valve bridge guide column:

[0058] The shaft support 3 is mounted on the valve bridge guide column 4 and is installed close to the fixed end by means of a clamping method. The shaft hole on the shaft support is perpendicular to the valve bridge guide column 4 and the vertical plane of the valve bridge 12, so that the vibration of the shaft support is consistent with the system. The outer ring of the expansion sleeve d39 is mounted on the shaft support 3, and the inner ring is mounted on the shaft 25, so that the motion state of the shaft support 3 is transmitted to the shaft 25. At the same time, the shaft 25 is mounted on the bearing d38, the bearing a24, the expansion sleeve c34, the expansion sleeve b33, and the expansion sleeve a23. The inner rings of the bearing d38 and the bearing a24 are mounted on the shaft 25, and the outer rings are mounted on the first bearing seat 13 and the second bearing seat 29; the inner ring of the expansion sleeve c34 is mounted on the shaft 25, and the outer ring is mounted on the inner ring of the bearing c35. The outer ring of the bearing c35 is mounted on the inner ring of the first crankshaft 37, so that the motion state of the first crankshaft 37 can be distinguished from that of the shaft 25. Open, but the vibration of the first crankshaft 37 is consistent with that of the shaft 25; the expansion sleeve b33 is installed with the shaft 25 and the inner ring of the bearing b32, and the bearing b32 is installed on the outer ring of the expansion sleeve b33 and the inner ring of the second crankshaft 31, so that the movement state of the second crankshaft 31 is distinguished from that of the shaft 25, but the vibration of the second crankshaft 31 is consistent with that of the shaft 25; the first bearing seat 13 and the second bearing seat 29 are installed on the valve bridge guide column fixing plane 1 by bolts, so that the vibration of the bearing seat and the shaft is consistent with the vibration of the system.

[0059] The scale plate 15 is mounted on the scale plate bracket 14. The scale plate 15 and the scale plate bracket 14 are fixed to the first bearing seat 13. The scale plate 15 is parallel to the plane connecting the two ends of the valve bridge 12. Ensure that the vibration frequency of the scale plate is consistent with the vibration of the system.

[0060] The third T-shaped pointer 21 is mounted on a third pointer bracket 22. The integral structure of the third pointer bracket 22 and the third T-shaped pointer 21 is connected via a locking sleeve a23 and secured to the shaft 25. This ensures that the motion of the third T-shaped pointer 21 is consistent with that of the shaft 25. The large surface area between the third T-shaped pointer 21 and the third pointer bracket 22 ensures minimal vibration at the tip of the third T-shaped pointer 21, ensuring that the T-shaped pointer's vibration is consistent with that of the system.

[0061] The axis of symmetry of the third T-shaped pointer 21 is collinear with the axis of the valve bridge guide post 4 and is located at the mid-perpendicular line of the valve bridge 12. The tip of the third T-shaped pointer 21 coincides with the "0" scale line on the scale plate 15. The motion of the third T-shaped pointer 21 and the scale plate 15 are separated by bearing d38.

[0062] 2. Measuring valve stroke part:

[0063] The first parallel plate 9 is connected to the valve spring seat 7 and the first crank-connecting rod mechanism 16. Because the motion trajectory of the valve spring seat is the same as that of the valve guide, and the motion trajectory of the valve guide is the same as that of the valve, the motion trajectory of the first parallel plate 9 and the right valve guide 6 is the same; the second parallel plate 18 is connected to the left valve spring seat and the second crank-connecting rod mechanism 20. Figure 2 In the figure, the outer circumferential surface of the first crankshaft 37 is connected to the first pointer bracket 36. The first crankshaft 37 and the first crank arm 41 are integrally formed. The first crank arm 41 and the connecting rod shaft 1-2 are integrally formed. The connecting rod shaft 1-2 and the connecting rod 1-3 are connected via the connecting rod bearing 1-6. The connecting rod 1-3 is connected to the connecting rod pin 1-4, which is connected to the connecting rod pin bracket 1-5. The connecting rod pin bracket 1-5 is connected to the first parallel plate 9. The stroke of the valve guide 6 is transmitted to the first parallel plate 9, then to the first crankshaft 37, and then to the first pointer bracket 36, and finally to the first T-shaped pointer 17. The second parallel plate 18 has the same motion trajectory as the left valve guide.

[0064] The motion of the two parallel plates is transmitted to the first crankshaft 37 and the second crankshaft 31, respectively, via the first crank-connecting rod mechanism 16 and the second crank-connecting rod mechanism 20. The first T-shaped pointer 17 is bolted to the first pointer bracket 36, and the first pointer bracket 36 and the first T-shaped pointer 17 are bolted to the first crankshaft 37. The second T-shaped pointer 19 is bolted to the second pointer bracket 30, and the third pointer bracket 22 and the third T-shaped pointer 21 are bolted to the second crankshaft 31. To ensure that the vibrations of the first and second T-shaped pointers 17 and 19 are consistent with the vibrations of the system, since both the second crankshaft 31 and the first crankshaft 37 are connected to the shaft 25 via bearings and expansion sleeves, the motion trajectories of the second and first crankshafts 31 and 37 are not disturbed by the shaft 25. Since the distance from the second crank-connecting rod mechanism 20 to the vertical plane of the valve bridge 12 is farther than the distance from the first crank-connecting rod mechanism 16 to the vertical plane of the valve bridge 12, and the distance from the second parallel plate 18 to the vertical plane of the valve bridge 12 is farther than the distance from the first parallel plate 9 to the vertical plane of the valve bridge 12, the motion trajectories of the above-mentioned two T-shaped pointers do not interfere with each other.

[0065] Vibration sensor 11 is mounted on vibration sensor support block 10. The unit formed by vibration sensor 11 and vibration sensor support 10 is mounted on vibration sensor bracket 2 via vibration sensor support block 10. Vibration sensor bracket 2 and the unit formed by the unit are mounted on valve bridge guide post fixing plane 1 via vibration sensor bracket 2. High-vibration-resistant high-speed camera 26 is mounted on a horizontal surface via high-vibration-resistant high-speed camera bracket 28. High-vibration-resistant high-speed camera 26 faces and focuses on the surface of dial 15. The center of gravity of vibration sensor 11 is aligned with the center of gravity of the three T-shaped pointers, the center of gravity of dial 15, and the center of gravity of high-vibration-resistant high-speed camera 26.

[0066] The two strong light sources 27 are aligned with the height of the high-vibration-resistant high-speed camera 26 and are symmetrically distributed about the camera 26. The two strong light sources 27 illuminate the T-shaped pointer (the scale), ensuring that the images taken by the high-vibration-resistant high-speed camera 26 are not blurred by light, thereby improving the accuracy of subsequent image recognition.

[0067] Principle: Uneven force on the valves causes abnormal valve motion trajectory, and the motion trajectories of the two valves are different; uneven force on the valves causes abnormal up and down reciprocating motion of the valve bridge. The abnormal motion of the valve bridge causes the valve bridge guide post to be subjected to a bending moment centered on the fixed end, and the valve bridge guide post will form a circular trajectory deformation around the fixed end as the center of the circle. The principle diagram is as follows Figure 6 shown.

[0068] Measuring the deformation of the valve bridge guide column:

[0069] The shaft bracket 3 is installed near the fixed end of the valve bridge guide column, and the deformation of the valve bridge guide column is transmitted to the shaft bracket 3. The lower end of the shaft bracket 3 is close to the fixed end of the valve bridge guide column 4. The lower end of the shaft bracket 3 will not be displaced, and the upper end of the shaft bracket 3 will be displaced due to the deformation of the valve bridge guide column 4. The shaft bracket 3 converts the displacement caused by the deformation into a rotation centered on the midpoint of the lower end of the shaft bracket 3. The shaft bracket 3 transmits the angle to the shaft 25, and the shaft 25 transmits the rotation angle to the whole formed by the third T-type pointer 21 and the third pointer bracket 22 through the expansion sleeve a23. The above-mentioned whole rotates around the axis, and the dial 15 is fixed to the measuring system and will not rotate. The picture obtained by taking pictures with a high-vibration-resistant high-speed camera 26 records the scale line on the dial 15 pointed by the third T-type pointer 21, and the change in the scale line value pointed by the third T-type pointer 21 is obtained by image recognition.

[0070] Measuring valve travel:

[0071] Take the right valve as an example: the valve stroke is converted into the stroke of the valve guide 6, the motion trajectory of the first parallel plate 9 is consistent with the valve spring seat 7, and the motion state of the valve spring seat 7 is consistent with that of the valve guide 6, then the motion trajectory of the first parallel plate 9 is consistent with the motion trajectory of the valve. The motion state of the first parallel plate 9 is transmitted to the connecting rod pin bracket 1-5, the motion state of the connecting pin bracket 1-5 is transmitted to the connecting rod 1-3 through the connecting pin 1-4, the motion state of the connecting rod 1-3 is transmitted to the connecting rod shaft 1-2, the motion state of the connecting rod shaft 1-2 is transmitted to the crank 1-1, the motion state of the crank 1-1 is transmitted to the first crank arm 41, the motion state of the first crank arm 41 is transmitted to the first crankshaft 37, the vertical reciprocating motion of the first parallel plate 9 is converted into the reciprocating rotational motion of the first crankshaft 37 through the first crank-connecting rod mechanism, the first crankshaft 37 drives the first pointer bracket 36 and the first T-shaped pointer 17 to form a whole to perform reciprocating rotational motion, and the scale plate 15 is fixed to the measuring system and will not rotate. The picture obtained by taking pictures with a high-vibration-resistant high-speed camera 26 records the scale line on the scale plate 15 pointed by the first T-shaped pointer 17, and the change in the scale line value pointed by the first T-shaped pointer 17 is obtained by image recognition. The valve stroke measurement principle on the left side is consistent with the above principle. Since the motion trajectories of the first T-shaped pointer 17 and the second T-shaped pointer 19 do not interfere with each other, the trajectory measurements of the valves on the left and right sides will not interfere with each other.

[0072] Make four marking points on the dial 15, such as Figure 4 As shown, based on the picture taken by the high-speed camera, the four marking points are identified, the marking point acquisition frequency of the image recognition pair and the vibration sensor acquisition frequency are set to the same frequency, and the motion law of the four marking points is obtained. The motion law of the four marking points is averaged to obtain the vibration law of the scale plate 15; the obtained vibration law of the scale plate 15 and the vibration data obtained by the vibration sensor 11 are averaged to obtain the vibration data of the entire measurement system, and the fingertips of the first T-type pointer and the fingertips of the second T-type pointer are dyed red and blue so that when the image recognition is performed later, the scale lines pointed by each fingertip do not interfere with each other, and the precise scale pointed by each pointer is obtained. After the image recognition high-vibration-resistant high-speed camera 26 obtains the data of the scale line value pointed by the T-type pointer on the photo, the vibration data of the test system is subtracted to eliminate the influence of vibration, so as to obtain accurate scale change values ​​ΔX1, ΔX2 and ΔX3 pointed by the third T-type pointer 21, the first T-type pointer 17 and the second T-type pointer 19.

[0073] Calculation process (such as Figure 6 The measurement principle diagram is shown as follows):

[0074] For the valve bridge deformation measurement, the accurate scale change value indicated by the third T-shaped pointer 21 is converted by the ratio of the change value ΔX1 to the circumference (the distance from the top end of the scale line "0" on the dial (point B) to the center line of the shaft is the radius R1) to obtain the rotation angle of the third T-shaped pointer 21, which is the rotation angle θ of the shaft 25, that is, the rotation angle θ1 of the shaft bracket 3. That is:

[0075]

[0076] Based on the rotation angle θ1 of the shaft support 3 and the distance r1 from the contact point between the shaft support 3 and the valve bridge guide post (contact point A near the suspended end) to the shaft centerline, the deformation trajectory of the valve bridge guide post near the fixed end is obtained. The deformation of the valve bridge guide post caused by uneven valve force is obtained as:

[0077]

[0078] For the right valve stroke during valve stroke measurement, the accurate change in the scale indicated by the first T-shaped pointer 17 is converted into the rotation angle θ2 of the first T-shaped pointer 17 by the ratio of the change value ΔX2 to the circumference (the distance from the upper end of the scale line "0" (point B) on the dial to the axis is the radius R1). This is the rotation angle θ2 of the first crankshaft 37, which is the rotation angle θ2 of the connecting rod shaft 1-2. That is:

[0079]

[0080] like Figure 1As shown, the axis centerline is defined as l1, and the intersection of the plane where the first crank arm 41 moves and the axis centerline l1 is inside the first crankshaft, which is defined as point O; the centerline of the connecting rod pin is l2, which is also the centerline of the connecting rod head at the upper end of the connecting rod, and the centerline of the connecting rod shaft is l3, which is also the centerline of the connecting rod head at the lower end of the connecting rod; the intersection of the plane where the connecting rod moves and the connecting rod pin centerline l2 is point D, and the intersection with the connecting rod shaft centerline l3 is point E; the foot of the perpendicular obtained by drawing a perpendicular line from point D to the first parallel plate is point C; line segment CD is the distance from the first parallel plate to the connecting rod pin centerline (l2), the length of line segment DE is the distance between the centerlines of the two ends of the connecting rod (l2 and l3), and point C is on the parallel plate, point D is on l2, and point E is on l3; the centerline of the connecting rod pin after the valve guide column is displaced is l′2, and the centerline of the connecting rod shaft after the valve guide column is displaced is l′3; The previously defined points D and E are changed to points D′ and E′, where DD′ represents the displacement of the parallel plate, that is, the displacement of the valve guide, and EE′ represents the straight-line distance between the center lines of the lower end of the connecting rod before and after the displacement of the valve guide; the intersection of the extended line of CD and OE′ is point F; the difference between DE and D′E′ is the position, while the lengths are both the distances between the center lines of the two ends of the connecting rod, DD′ is the displacement of the parallel plate, that is, the displacement of the valve guide, and EE′ is the straight-line distance between the center lines of the lower end of the connecting rod before and after the displacement of the valve guide, and the intersection of the extended line of OE and D′E′ is point G. According to the rotation angle θ2 of the first crankshaft 37, the angle ∠OEF between the crank arm and the connecting rod at the time of initial installation, the distance r2 from the axis of the connecting rod shaft 1-2 to the axis of the first crankshaft 37, and the distance DE between the center lines of the two ends of the connecting rod, the motion trajectory DD′ of the valve guide can be obtained.

[0081] Because the value of r2 is larger than DD′, the crank rotates at a small angle during the entire measurement process, so the value of ∠E′D′E will not be very large. After obtaining the value of θ2, we can calculate:

[0082]

[0083] ∠GEE′=π-∠OEE′

[0084]

[0085] ∠OFE=π-∠OEF-θ2

[0086] ∠E′EF=∠OEE′-∠OEF

[0087]

[0088] Because DE=DD′, From the law of sine we get:

[0089]

[0090] Find the value of ∠ED′E′ and we can get:

[0091]

[0092] ∠ED′E′=arcsin(sin∠ED′E′)

[0093] ∠EE′D′=π-∠D′EE′-∠ED′E′

[0094]

[0095] For the valve stroke on the left side, the calculation process is the same as the above process. The different values ​​are the scale change value ΔX3 and its corresponding quantity: the pointer rotation angle θ3, and the two points D″ and E″.

[0096] ΔS2=DE-D″E

[0097]

[0098] Due to the uneven force on the valve, the difference in valve stroke on the left and right sides is:

[0099]

[0100] The moving parts involved in the valve stroke and valve bridge guide column deformation measurement of the present invention are in direct contact, and the transmission error caused is extremely small and can be ignored. The valve bridge guide column deformation and valve stroke can be measured simultaneously, and can also be measured separately. The disassembly and assembly are simple, and the accuracy of the high-speed camera and the dial, as well as the dimensions of the various components of the device can be selected according to actual conditions and needs.

Claims

1. A measuring device for measuring valve stroke difference and valve bridge deformation, characterized in that: The invention comprises a valve bridge guide column fixing plane (1) and a shaft (25); a valve bridge guide column (4), a first bearing seat (13) and a second bearing seat (29) located on the same straight line are fixedly arranged in sequence on the valve bridge guide column fixing plane (1); the valve bridge guide column (4) is vertically arranged, and the suspended end at the top thereof cooperates with the guide hole of the valve bridge (12), so that the valve bridge (12) slides up and down along the valve bridge guide column (4); a shaft bracket (3) is fixedly arranged at the bottom of the valve bridge guide column (4); One end of the shaft (25) is fixed in the shaft bracket (3), and the other end is sequentially inserted into the bearings of the first bearing seat (13) and the second bearing seat (29); a vertical scale plate bracket (14) is fixedly provided on the first bearing seat (13), and a scale plate (15) is provided on the top of the scale plate bracket; A third pointer bracket (22) is fixedly provided on the shaft (25) near the second bearing seat (29), and a third T-shaped pointer (21) that matches the height of the scale plate (15) is fixedly provided on the top of the third pointer bracket (22); It also includes a valve force transmission mechanism with the same structure vertically arranged on the left and right sides of the valve bridge guide column (4), and a first pointer bracket (36) and a second pointer bracket (30) arranged between the first bearing seat (13) and the third pointer bracket (22); The valve force transmission mechanism includes a vertically arranged valve guide column (6) and a valve spring (5) sleeved on the valve guide column (6); the bottom of the valve guide column (6) is movably inserted into the valve bridge guide column fixed plane (1), and the top is fixedly provided with a valve spring seat (7) and is located at the lower part of the valve bridge (12). It moves downward together with the pressure brought by the downward movement of the valve bridge (12); the bottom of the valve spring (5) abuts against the valve bridge guide column fixed plane (1), and the top is limited by the valve spring seat (7). and rebounding the valve guide column (6) when the pressure of the valve bridge (12) is released; The valve spring seats of the two valve force transmission mechanisms are respectively fixed to one end of the first parallel plate (9) and the second parallel plate (18); the other end of the first parallel plate (9) is connected to a first crankshaft (37) mounted on the shaft (25) via a bearing sleeve through a first crank-connecting rod mechanism (16); the other end of the second parallel plate (18) is connected to a second crankshaft (31) mounted on the shaft (25) via a bearing sleeve through a second crank-connecting rod mechanism (20); The first crankshaft (37) and the second crankshaft (31) are fixedly connected to the bottom end of the first pointer bracket (36) and the bottom of the second pointer bracket (30), respectively; the tops of the first pointer bracket (36) and the second pointer bracket (30) are respectively provided with a first T-shaped pointer (17) and a second T-shaped pointer (19) that match the height of the scale plate (15); It also includes a high-speed vibration-resistant camera (26) arranged on one side of the second bearing seat (29) for photographing scale changes of the first T-shaped pointer (17), the second T-shaped pointer (19) and the third T-shaped pointer (21).

2. The measuring device for measuring valve stroke difference and valve bridge deformation according to claim 1, characterized in that: A vibration sensor bracket (2) is also provided on the valve bridge guide column fixing plane (1), and a vibration sensor (11) is provided on the top of the vibration sensor bracket (2) via a vibration sensor support block (10); the center of gravity height of the vibration sensor (11) is consistent with the center of gravity heights of the three T-shaped pointers, the center of gravity height of the dial (15), and the center of gravity height of the high-vibration-resistant high-speed camera (26).

3. The measuring device for measuring valve stroke difference and valve bridge deformation according to claim 1, characterized in that: The first crank-connecting rod mechanism (16) comprises a first crank arm (41) and a connecting rod (1-3), one end of the first crank arm (41) is fixedly connected to the first crankshaft (37), and the other end is fixedly connected to the connecting rod shaft (1-2), and the connecting rod shaft (1-2) and the connecting rod (1-3) are fixedly connected. The bottom end is rotatably connected via a connecting rod bearing (1-6); the top end of the connecting rod (1-3) is rotatably connected to a connecting rod pin bracket (1-5) via a connecting rod pin (1-4); the connecting rod pin bracket (1-5) is fixed to the bottom of the first parallel plate (9); the second crank-connecting rod mechanism (20) and the first crank-connecting rod mechanism (16) have the same structure.

4. The measuring device for measuring valve stroke difference and valve bridge deformation according to claim 1, characterized in that: The inner wall of the first crankshaft (37) / the second crankshaft (31) is sleeved with an outer ring of a bearing, and the inner ring of the bearing is mounted on the shaft (25) via a tightening sleeve.

5. The measuring device for measuring valve stroke difference and valve bridge deformation according to claim 1, characterized in that: The high-vibration-resistant high-speed camera (26) is arranged on a high-vibration-resistant high-speed camera bracket (28), and strong light sources (27) are symmetrically arranged on both sides thereof, and the two strong light sources (27) are at the same height as the high-vibration-resistant high-speed camera (26).

6. A method for measuring valve bridge deformation using the device for measuring valve stroke difference and valve bridge deformation according to claim 2, characterized in that: The following steps are involved: Step 1: Take a photo with a high-speed, vibration-resistant camera to record the scale line on the dial pointed by the third T-shaped pointer, and obtain the change value ΔX1 of the scale line pointed by the third T-shaped pointer through image recognition; Step 2: Calculate the circumference of a circle with radius R1, which is the distance from point B on the top of the scale line 0 to the center line of the shaft. The rotation angle of the third T-pointer is the rotation angle θ of the shaft, which is the rotation angle θ1 of the shaft bracket: Step 3: Based on the rotation angle θ1 of the shaft bracket and the distance r1 between the fixed point A of the valve bridge guide post and the upper edge of the shaft bracket and the shaft centerline, the deformation trajectory circle of the valve bridge guide post near the fixed end is obtained; the deformation amount of the valve bridge guide post caused by uneven valve force is obtained as:

7. The method according to claim 6, characterized in that The step 1 is specifically as follows: Make four marking points on the dial, perform marking point recognition on the four marking points, set the marking point acquisition frequency of the image recognition pair and the vibration sensor acquisition frequency to the same frequency, obtain the motion law of the four marking points, and calculate the average of the motion law of the four marking points to obtain the vibration law of the dial; calculate the average of the obtained vibration law of the dial and the vibration data obtained by the vibration sensor to obtain the vibration data of the entire measurement system; color the fingertip of the third T-type pointer, obtain the data of the scale line pointed by the third T-type pointer in the photo through image recognition and high-vibration-resistant high-speed camera, and then subtract the vibration data of the test system to eliminate the influence of vibration and obtain the accurate scale change value ΔX1 of the third T-type pointer.

8. A method for measuring valve stroke difference using the device for measuring valve stroke difference and valve bridge deformation according to claim 2, characterized in that: The following steps are involved: Step a: taking photos with a high-speed, vibration-resistant camera to record the scale line on the dial pointed by the first T-shaped pointer, and obtaining a change value ΔX2 of the scale line pointed by the first T-shaped pointer through image recognition; Step b: Calculate the circumference of a circle with a radius R1, which is the distance from the uppermost endpoint B of the scale line 0 to the centerline of the shaft. Calculate the rotation angle θ2 of the first T-shaped pointer, which is the rotation angle θ2 of the first crankshaft, which is the rotation angle θ2 of the connecting rod shaft: Step c: define the center line of the shaft (25) as l1, the intersection of the plane where the first crank arm (41) moves and the shaft center line l1 is inside the first crankshaft, and is defined as point O; the center line of the connecting rod pin is l2, and the center line of the connecting rod shaft is l3; the intersection of the plane where the connecting rod moves and the connecting rod pin center line l2 is point D, and the intersection with the connecting rod shaft center line l3 is point E; the foot of the perpendicular obtained by drawing a perpendicular line from point D to the first parallel plate is point C; Define the connecting rod pin centerline after the valve guide is displaced as l ′ 2. The center line of the connecting rod shaft is l ′ 3; the corresponding points D and E change to points D′ and E′ respectively; Then DD′ represents the displacement of the parallel plate, that is, the displacement of the valve guide; EE′ represents the displacement of the connecting rod shaft before and after the valve guide is displaced; the intersection of the extended line of CD and OE′ is point F; Based on the rotation angle θ2 of the first crankshaft, the angle ∠OEF between the first crank arm and the connecting rod at the time of initial installation, the distance r2 from the axis of the connecting rod shaft to the axis of the first crankshaft, the distance DE between the center lines of the two ends of the connecting rod, and the straight-line distance EE′ between the center lines of the lower ends of the connecting rod before and after the valve guide is displaced, the distance D between the center line of the connecting rod pin l2 after the valve guide is displaced and the center line of the connecting rod shaft l3 before the valve guide is displaced is calculated. ′ E is: Among them, the angle and bring in Then the valve stroke ΔS1 at the first parallel plate is: Step d: Similarly, the stroke ΔS2 of the valve at the second parallel plate is: Step e: Due to the uneven force on the valve, the difference in valve stroke on the left and right sides is:

9. The method according to claim 8, characterized in that The step a is specifically as follows: Four marking points are made on a scale plate, and the marking points are identified. The marking point acquisition frequency of the image recognition pair and the vibration sensor acquisition frequency are set to the same frequency to obtain the motion law of the four marking points. The motion law of the four marking points is averaged to obtain the vibration law of the scale plate; the obtained vibration law of the scale plate and the vibration data obtained by the vibration sensor are averaged to obtain the vibration data of the entire measurement system, the fingertips of the first T-type pointer and the fingertips of the second T-type pointer are colored with different colors, and the data of the scale line pointed by the T-type pointer on the photo is obtained by an image recognition high-vibration-resistant high-speed camera, and then the vibration data of the test system is subtracted to eliminate the vibration influence, thereby obtaining accurate scale change values ​​ΔX2 and ΔX3 pointed by the first T-type pointer (17) and the second T-type pointer (19).

Images