A crab vehicle four-wheel positioning tool and adjusting method

Abstract

The application discloses a kind of crab vehicle four-wheel alignment tooling, first tooling is used to determine axle axis reference, second tooling is used to determine the perpendicularity of rear axle axis and frame axis, third tooling and fourth tooling are used to assist complete the adjustment of front, rear wheel toe.A kind of adjustment method using crab vehicle four-wheel alignment tooling, using first tooling to determine axle axis reference→based on axle axis reference, using second tooling to assist and adjust rear axle assembly, ensure the perpendicularity of rear axle axis, front axle axis and frame axis→based on the above adjustment, using third tooling and fourth tooling to assist and adjust steering tie rod, ensure the perpendicularity of left rear tire and rear axle axis→adjust rear axle assembly front side steering cross tie rod, so that rear axle toe meets technical index.For crab vehicle structure, design a set of auxiliary tooling, and determine the perpendicularity of each axis using tooling, ensure the accuracy of front, rear wheel toe adjustment, simple operation, high adjustment accuracy.

Description

Technical Field

[0001] This invention belongs to the field of four-wheel alignment adjustment technology, specifically relating to a four-wheel alignment fixture and adjustment method for a crab-walking vehicle. Background Technology

[0002] Crab-walking vehicles are devices capable of three steering modes: two-wheel steering, four-wheel steering, and crab-walking steering, which can be switched arbitrarily according to working conditions. Due to their high speed, higher requirements are placed on driving safety and stability, making four-wheel alignment adjustment particularly important. Furthermore, because the rear axle is not a traditional fixed axle structure, performing four-wheel alignment is quite difficult. Currently, there is no complete and dedicated method for adjusting this type of vehicle.

[0003] CN113415310A discloses a wheel adjustment method and system. It measures and calculates the perpendicularity error between the wheel axle and the vehicle's running direction, calculates the adjustment amount for the wheel axle based on the perpendicularity error, then processes a corresponding eccentric bearing sleeve based on the obtained adjustment amount, and finally installs the eccentric bearing sleeve on the wheel, making the wheel axle perpendicular to the running direction, thereby solving the wheel wear problem. However, this patent is not applicable to the adjustment and determination of the axle of this specific vehicle. CN113954964A discloses a vehicle toe-in adjustment method, including: obtaining the vehicle's target toe-in value, current toe-in value, and the pitch value of the thread on the steering tie rod; calculating the adjustment angle of the steering tie rod based on the target toe-in value, the current toe-in value, and the pitch value; and adjusting the steering tie rod according to the adjustment angle to adjust the vehicle from the current toe-in value to the target toe-in value. If the target toe-in value, current toe-in value, and pitch value are obtained with sufficient accuracy, the final angle to be adjusted will be precise. Therefore, the car can be adjusted from the current toe-in value to the target toe-in value based on the angle to be adjusted. Although this method discloses a method for adjusting the toe-in value using a steering tie rod, the determination and measurement methods of various references used in this method are not applicable to this vehicle. This vehicle requires special auxiliary tools for adjustment.

[0004] Therefore, based on the structural characteristics of the front and rear axles of the crab-walking vehicle, the present invention adopts a simple and ingenious method, with the help of a set of auxiliary tooling and workstation equipment, to solve the problem of difficult four-wheel alignment adjustment of the vehicle. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide a four-wheel alignment fixture and adjustment method for crab-like vehicles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a tooling for four-wheel alignment of a crab-like vehicle, comprising a first tooling, a second tooling, a third tooling, and a fourth tooling. The first tooling is used to determine the axle axis reference, the second tooling is used to determine the perpendicularity of the rear axle axis to the frame axis, and the third and fourth toolings are used to assist in adjusting the toe-in of the front and rear wheels.

[0007] The first fixture is an "L"-shaped plate, with a fixture hole at the top of the long side plate and an installation hole at the top of the short side plate.

[0008] The second tooling is a screw with an integrated upper and lower part. The upper radius of the screw is smaller than the lower radius. The upper screw has a groove on its circumference, and the lower screw has a threaded hole inside.

[0009] The third tooling is a screw, and the fourth tooling is a rectangular tube. The rectangular tube has mounting holes that are compatible with the third tooling, and tooling holes are also provided at both ends.

[0010] An adjustment method using a four-wheel alignment fixture for a crab-walking vehicle includes the following steps:

[0011] Step 1: Use the first tooling to determine the axle axis reference;

[0012] Step 2: Based on the axle axis reference, use the second tooling to assist and adjust the rear axle assembly to ensure the perpendicularity of the rear axle axis, front axle axis and frame axis;

[0013] Step 3: Based on the above adjustments, use the third and fourth tools to assist and adjust the steering tie rod to ensure the perpendicularity of the left rear tire to the rear axle axis;

[0014] Step 4: Adjust the front steering tie rod of the rear axle assembly to ensure that the rear axle toe-in meets the technical specifications.

[0015] Step 5: Adjust the front axle toe-in following the methods in steps 3 and 4.

[0016] In step 1, the mounting hole of the first tooling is inserted into the stud on the stepped surface of the main drive seat flange. The tooling hole of the first tooling is within the standard dimension from the bend. Therefore, the position of the tooling hole is the simulated vertical position of the axle axis.

[0017] Before proceeding to step 2, park the test vehicle on a level surface and prop it up with a stool.

[0018] In step 2, the adjustment of the rear axle axis perpendicular to the frame axis is as follows: Remove the nuts on the left and right sides of the rear axle assembly, and install the screw holes of the lower screw of the second tooling onto the studs. Hang the plumb bobs on the grooves of the two upper screws of the second tooling and the inside of the grease fittings on the left and right sides of the frame. Adjust the height of the four plumb bobs to be off the horizontal ground and level with it. The projection formed by the four plumb bobs constitutes line segments L1, L2, L3 and L4. Loosen the nuts on the U-bolts of the leaf springs of the rear axle assembly, and adjust the rear axle assembly so that |L1-L2|≤3mm and |L3-L4|≤5mm to ensure the perpendicularity of the rear axle axis to the frame axis.

[0019] In step 2, the vertical adjustment of the front axle axis and the frame axis is as follows: retain the plumb bob on the rear axle assembly frame, suspend the plumb bobs on the left and right sides of the front axle assembly using the second tool, adjust the height of the four plumb bobs to be off the horizontal ground and level, and the projections of the front and rear axle plumb bobs form L5, L6, L7, and L8. Finally, loosen the nuts on the U-bolts of the front axle assembly leaf springs, adjust the installation position of the front axle assembly and the frame so that |L5-L6|≤5mm and |L7-L8|≤8mm, ensuring the perpendicularity of the front axle axis and the frame axis.

[0020] In step 3, the two third fixtures are installed into the two top holes of the left rear wheel core. Then, the mounting hole of the fourth fixture is inserted into the screw of the third fixture. Finally, the level measuring instrument is placed directly above the rectangular tube, and the tire is manually rotated to make the level measuring instrument reading 0°.

[0021] After confirming that the level measuring instrument reading is 0°, install two plumb bobs on the tooling holes at both ends of the fourth tooling respectively. At the same time, also suspend a plumb bob at the center of the frame axis. The projections of the three plumb bobs form lines AB and BC. Then adjust the steering tie rod so that AC = BC, ensuring that the left rear tire is perpendicular to the rear axle axis.

[0022] After aligning the left rear tire with the rear axle axis, place the dial indicator at the lower end of the fourth tooling, adjust the extension of the rear axle short steering tie rod assembly, rotate the dial indicator to a fixed angle, and finally secure the steering tie rod bolts.

[0023] In step 4, the third and fourth fixtures are installed onto the two rear wheels according to the installation method in step 3. The plumb bob is then hung into the tooling holes of the two fourth fixtures, projecting to form L9 and L10.

[0024] Adjust the front steering tie rod of the rear axle assembly to make L9-L10=6mm, ensuring that the rear axle toe-in meets the technical specifications.

[0025] The adjustment method for the front axle toe-in is the same as that for the rear axle toe-in.

[0026] Compared with the prior art, the present invention has the following advantages: For the crab-like vehicle structure, which uses steering axles for both the front and rear axles, an auxiliary tooling is designed and the perpendicularity of each axis is determined by the tooling, so as to ensure the accuracy of the front and rear wheel toe-in adjustment. The operation is simple and the adjustment accuracy is high. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a front view of the first tooling in this invention;

[0029] Figure 2 This is a top view of the first tooling in this invention;

[0030] Figure 3 This is a side view of the first tooling in this invention;

[0031] Figure 4 This is a front view of the second tooling in this invention;

[0032] Figure 5 This is a top view of the second tooling in this invention;

[0033] Figure 6 for Figure 4 Sectional view of AA;

[0034] Figure 7 This is a front view of the third tooling in this invention;

[0035] Figure 8 This is a top view of the third tooling in this invention;

[0036] Figure 9 This is a front view of the fourth tooling in this invention;

[0037] Figure 10 This is a top view of the fourth tooling in this invention;

[0038] Figure 11 for Figure 9 Enlarged view of point B;

[0039] Figure 12 This is a schematic diagram of the four-wheel alignment reference for the crab-walking vehicle in this invention;

[0040] Figure 13 This is a schematic diagram of the vertical direction of the axle axis of the crab-walking vehicle using the first tooling in this invention;

[0041] Figure 14 This is a schematic diagram of the installation of the second tooling for the crab-walking vehicle in this invention;

[0042] Figure 15 for Figure 14 A schematic diagram of the projection of the four plumb bobs installed in the middle;

[0043] Figure 16 This is a schematic diagram of the plumb bob projection of the front and rear axles of the crab-walking vehicle in this invention;

[0044] Figure 17 This is a schematic diagram of the third and fourth tooling of the crab-walking vehicle in this invention being installed on the left rear wheel;

[0045] Figure 18 This is a schematic diagram showing the installation of the percentage table for the crab-walking vehicle in this invention;

[0046] Figure 19 This is a schematic diagram of the rear axle toe-in adjustment in the crab-walking vehicle of the present invention;

[0047] In the diagram, 1-first tooling; 2-second tooling; 3-third tooling; 4-fourth tooling; 5-steering tie rod; 6-steering cross tie rod; 7-inner side of grease fitting; 8-dial indicator; 9-level measuring instrument; 10-frame reference; 11-rear axle axis; 12-front axle axis; D-plumb bob. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0049] Reference Figure 1-11 A tooling for four-wheel alignment of a crab-like vehicle includes a first tooling 1, a second tooling 2, a third tooling 3, and a fourth tooling 4. The first tooling 1 is used to determine the axle axis reference, the second tooling 2 is used to determine the perpendicularity of the rear axle axis to the frame axis, and the third and fourth toolings are used to assist in adjusting the toe-in of the front and rear wheels.

[0050] Reference Figure 1-3 The first fixture (1) is an "L" shaped plate with a fixture hole at the top of the long side plate and an installation hole at the top of the short side plate.

[0051] Reference Figure 4-6 The second tooling, 2, is a screw rod consisting of an upper and a lower integrated part. The upper radius of the screw rod is smaller than the lower radius. The upper screw rod has a groove on its circumference, and the lower screw rod has a threaded hole inside.

[0052] Reference Figure 7-11 The third tooling 3 is a screw, and the fourth tooling 4 is a rectangular tube. The rectangular tube has mounting holes that are compatible with the third tooling 3, and tooling holes are also provided at both ends.

[0053] This adjustment method is mainly applied to vehicles with a crab-like driving pattern. Due to the vehicle's structural design, the kingpin inclination angle and wheel camber angle are fixed values ​​and cannot be adjusted. This method primarily addresses the difficulty in adjusting the front and rear wheel toe-in during four-wheel alignment. The method is as follows:

[0054] 1. Preparation

[0055] Both the front and rear axles of the vehicle are steering axles. To ensure stability at high speeds when both wheels are steering, the rear axle wheel alignment must meet the requirements of a fixed axle (the radial section at the tire center is perpendicular to the axle axis). To adjust the wheel alignment, the axle axis must first be identified as a reference. Since the rear axle is already an assembly, the axis reference cannot be determined visually; therefore, it must be simulated through reference conversion. See [link to relevant documentation]. Figure 12 Show.

[0056] The dimension from the main drive unit mounting surface to the rear axle axis is 70 + 0.1 mm according to the process specifications. The thickness of the main drive unit flange is 12 mm. (Refer to...) Figure 1-3 First fixture 1 is fabricated. First fixture 1 is an "L"-shaped plate with a fixture hole at the top of the long side and an mounting hole at the top of the short side. (Small fixture holes) The distance from the bending surface is 70 + 12 = 82 mm; insert the mounting hole of the first tooling 1 into the stud on the stepped surface of the main drive seat flange. The position of the small hole in the tooling is the simulated vertical position of the axle axis. See Figure 13 Show.

[0057] 2. Adjustment process

[0058] 1) Park the test vehicle on a level surface and prop it up with a stool;

[0059] 2) Remove the nuts on the left and right sides of the rear axle assembly, and install the screw holes of the lower screw of the second tooling 2 onto the studs. Hang the plumb bob D in the grooves of the two upper screws of the second tooling 2 and inside the grease fittings 7 on the left and right sides of the frame. Adjust the height of the plumb bob D to 1-2mm above the horizontal ground. See Figure 14 The projection formed by the four plumb bobs D is shown below. Figure 15 Then, loosen the nuts on the U-bolts of the leaf springs of the rear axle assembly, and adjust the rear axle assembly so that |L1-L2|≤3mm and |L3-L4|≤5mm, ensuring the perpendicularity of the rear axle axis 11 to the frame axis.

[0060] 3) Remove the nuts on both the left and right sides of the front axle assembly, and install the second tooling 2 screws onto the studs respectively. Hang the plumb bob D in the groove of the second tooling 2 screw, and adjust the height of the plumb bob D to 1-2mm above the horizontal ground. The projections of the plumb bob D on the front and rear axles are shown in the figure. Figure 16 As shown, loosen the nuts on the U-bolts of the leaf springs of the front axle assembly, and adjust the installation position of the front axle assembly and the frame so that |L5-L6|≤5mm and |L7-L8|≤8mm, ensuring the perpendicularity of the front axle axis 12 to the frame axis.

[0061] 4) Install the third tooling 3 into the two top holes of the left rear wheel hub. Then, insert the mounting hole of the fourth tooling 4 into the screw of the third tooling 3. Finally, place the level measuring instrument 9 directly above the rectangular tube and manually rotate the tire until the level measuring instrument reading is 0°. Install the two plumb bobs D onto the tooling holes at both ends of the fourth tooling 4, and simultaneously suspend plumb bobs D at the center of the frame axle. The projections of the three plumb bobs D form lines AB and BC, see... Figure 17 Instructions: Adjust the steering tie rod so that AC = BC, ensuring the left rear tire is perpendicular to the rear axle axis. Set the dial indicator to... Figure 18 Position as shown, adjust the rear axle short steering tie rod 5 assembly (extended) so that the dial indicator rotates 1.5mm, and fix the steering tie rod 5 bolts.

[0062] 5) Retain the third tool 3 and the fourth tool 4 on the left rear tire. Then, install the third tool 3 into the two top holes of the right rear wheel hub. Insert the mounting hole of the fourth tool 4 into the screw of the third tool 3. Finally, place the level measuring instrument 9 directly above the two rectangular tubes and manually rotate the tire until the level measuring instrument reading is 0°. Install the plumb bob D into the tooling holes of the two fourth tools, projecting them to form L9 and L10, see... Figure 19 As shown, adjust the front steering tie rod 6 of the rear axle assembly so that L9-L10=6mm, ensuring that the rear axle toe-in meets the technical specifications.

[0063] 6) Adjust the front axle toe-in according to steps 4) and 5).

[0064] 7) The vehicle was tested and adjusted, and there was no deviation or fishtailing when driving at high speed.

[0065] The foregoing has provided a detailed description of the four-wheel alignment fixture and adjustment method for crab-walking vehicles provided by this invention. Specific examples have been used to illustrate the structure and working principle of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. An adjustment method using a four-wheel alignment fixture for a crab-walking vehicle, characterized in that: The positioning fixture includes a first fixture (1), a second fixture (2), a third fixture (3) and a fourth fixture (4). The first fixture (1) is used to determine the axle axis reference, the second fixture (2) is used to determine the perpendicularity of the rear axle axis to the frame axis, and the third fixture (3) and the fourth fixture are used to assist in completing the adjustment of the front and rear wheel toe-in. The first tooling (1) is an "L" shaped plate with a tooling hole at the top of the long side plate and an installation hole at the top of the short side plate; the second tooling (2) is a screw rod with an integrated upper and lower part, the upper radius of the screw rod is smaller than the lower radius, the upper screw rod has a groove on its circumference, and the lower screw rod has a threaded hole inside; the third tooling (3) is a screw rod, and the fourth tooling (4) is a rectangular tube with an installation hole on the rectangular tube that matches the third tooling (3), and tooling holes are also provided at both ends; The adjustment method includes the following steps: Step 1: Use the first tooling (1) to determine the axle axis reference. Insert the mounting hole of the first tooling (1) into the stud on the step surface of the main drive seat flange. The tooling hole of the first tooling (1) meets the standard size from the bend. Then the position of the tooling hole is the simulated position of the vertical direction of the axle axis. Step 2: Based on the axle axis reference, the second tool (2) is used to assist and adjust the rear axle assembly to ensure the perpendicularity of the rear axle axis, the front axle axis and the frame axis. The adjustment of the rear axle axis perpendicular to the frame axis is as follows: Remove the nuts on the left and right sides of the rear axle assembly, and install the screw holes of the lower screw of the second tool (2) onto the studs respectively. Hang the plumb bobs on the grooves of the upper screws of the two second tool (2) and the inside of the grease nipples (7) on the left and right sides of the frame. Adjust the height of the four plumb bobs to be off the horizontal ground and level. The projection formed by the four plumb bobs constitutes the line segments L1, L2, L3 and L4. Loosen the nuts on the U-bolts of the leaf spring of the rear axle assembly, and adjust the rear axle assembly so that |L1-L2|≤3mm, |L3-L4|≤5mm, to ensure the perpendicularity of the rear axle axis and the frame axis. The vertical adjustment of the front axle axis and the frame axis is as follows: Keep the plumb bob on the rear axle assembly frame, use the second tool (2) to suspend the plumb bob on the left and right sides of the front axle assembly, adjust the height of the four plumb bobs to be off the horizontal ground and level, and the projection of the front and rear axle plumb bobs forms L5, L6, L7, L8. Finally, loosen the nuts on the U-bolts of the front axle assembly leaf spring, adjust the installation position of the front axle assembly and the frame so that |L5-L6|≤5mm, |L7-L8|≤8mm, and ensure the perpendicularity of the front axle axis and the frame axis. Step 3: Based on the above adjustments, use the third tool (3) and the fourth tool (4) to assist and adjust the steering tie rod (5) to ensure the perpendicularity of the left rear tire to the rear axle axis; Step 4: Adjust the front steering tie rod (6) of the rear axle assembly to ensure that the rear axle toe-in meets the technical specifications; Step 5: Adjust the front axle toe-in following the methods in steps 3 and 4.

2. The adjustment method using the four-wheel alignment fixture for crab-like vehicles according to claim 1, characterized in that: In step 3, the two third fixtures (3) are installed into the two top holes of the left rear wheel core, and then the mounting hole of the fourth fixture (4) is inserted into the screw of the third fixture (3). Finally, the level measuring instrument (9) is placed directly above the rectangular tube, and the tire is manually rotated so that the reading of the level measuring instrument (9) is 0°.

3. The adjustment method using the four-wheel alignment fixture for crab-like vehicles according to claim 2, characterized in that: After confirming that the reading of the level measuring instrument (9) is 0°, install two plumb bobs on the tool holes at both ends of the fourth tool (4) respectively, and at the same time, suspend plumb bobs at the center of the frame axis. The projection of the three plumb bobs forms AB and BC lines. Then adjust the steering tie rod (5) to make AC=BC, ensuring that the left rear tire is perpendicular to the rear axle axis.

4. The adjustment method using the four-wheel alignment fixture for crab-like vehicles according to claim 3, characterized in that: After the left rear tire is perpendicular to the rear axle axis, place the dial indicator (8) at the lower end of the fourth tool (4), adjust the extension of the rear axle short steering tie rod assembly, rotate the dial indicator (8) to a fixed angle, and finally fix the steering tie rod bolt.

5. The adjustment method using the four-wheel alignment fixture for crab-like vehicles according to claim 1, characterized in that: In step 4, the third tooling (3) and the fourth tooling (4) are installed on the two rear wheels according to the installation method in step 3. The plumb bob is hung in the tooling holes of the two fourth tooling (4) and projected to form L9 and L10.

6. The adjustment method using the four-wheel alignment fixture for crab-like vehicles according to claim 5, characterized in that: Adjust the front steering tie rod (6) of the rear axle assembly to make L9-L10=6mm, ensuring that the rear axle toe-in meets the technical specifications.

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