Differential spider positioning method and device

Abstract

The invention relates to the technical field of universal joint pin universal joints, in particular to a differential universal joint pin positioning method and device. Pre-positioning the cross shaft in the first positioning assembly by taking one of the positioning planes and the positioning hole of the cross shaft as a reference; under the state that pre-positioning is completed, the positioning plane is attached to the positioning base, the positioning hole is matched with the positioning pin in an inserted mode, and the included angle between the to-be-machined shaft head of the cross shaft and the preset axis is smaller than a threshold value; on the basis of completion of pre-positioning, a second positioning assembly is controlled to move towards the cross shaft along the preset axis, so that the to-be-machined shaft head is in a first abutting state and a second abutting state in sequence; and on the basis that the to-be-machined shaft head is in the second abutting state, the second positioning assembly is controlled to stop moving, then the pressing head is controlled to be matched with the positioning base to clamp the shaft body of the cross shaft, and finally the second positioning assembly is separated from the cross shaft. Therefore, the problem of poor positioning precision caused by trimming difference of the outer circumferential surface of the shaft head of the cross shaft blank is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cross-shaft universal joints, and in particular to a positioning method and device for a differential cross-shaft. Background Art

[0002] The differential is a core component in a vehicle's transmission system. Its primary function is to allow the left and right drive wheels to rotate at different speeds when the vehicle turns, thereby ensuring smooth steering and reducing tire wear and power loss. The planetary gear differential is one of the most common types of differentials. It consists of a differential case, a cross shaft, planetary gears, and axle gears. The cross shaft is fixed to the differential case and supports the freely rotating planetary gears. The cross shaft typically consists of a shaft body and four spindle heads extending outward from the body in four directions. Before machining the outer surface of the cross shaft blank and drilling the center hole for the spindle head, the cross shaft must be positioned on the machining machine. The accuracy of the cross shaft positioning is currently a pressing issue. Summary of the Invention

[0003] In order to solve the problem of poor positioning accuracy caused by the difference in cutting edges of the outer circumferential surface of the shaft head of a cross shaft blank, the present invention provides a positioning method and device for a differential cross shaft.

[0004] In a first aspect, the present invention provides a method for positioning a differential cross shaft, comprising:

[0005] The cross shaft is pre-positioned in the first positioning assembly based on one of the positioning planes and the positioning hole of the cross shaft; wherein the cross shaft comprises an integrally formed shaft body and four shaft heads; both end faces of the shaft body are the positioning planes; the positioning hole is located on the shaft body; the first positioning assembly comprises a positioning seat, a positioning pin and a pressure head; the positioning pin is fixedly connected to the positioning seat; when the pre-positioning is completed, the positioning plane is in contact with the positioning seat, the positioning hole is plugged into the positioning pin, and the angle between the shaft head to be processed of the cross shaft and the preset axis is less than a threshold value;

[0006] Based on the completion of the pre-positioning, the second positioning assembly is controlled to move along the preset axis toward the cross axis, so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence; wherein the second positioning assembly includes a first claw and a second claw; the first claw has an abutment plane; the second claw has two intersecting correction inclined surfaces; the abutment plane intersects with the correction inclined surfaces; when the shaft head is in the first abutment state, the abutment plane and one of the correction inclined surfaces abut against the shaft head at the same time; when the shaft head is in the second abutment state, the abutment plane and the two correction inclined surfaces abut against the shaft head at the same time, and the axis of the shaft head coincides with the preset axis;

[0007] Based on the shaft head to be processed being in the second abutment state, controlling the second positioning assembly to stop moving;

[0008] Based on the second positioning assembly being in a stationary state, controlling the pressing head to cooperate with the positioning seat to clamp the shaft body of the cross shaft;

[0009] Based on the first positioning assembly clamping the shaft body, the second positioning assembly is separated from the cross shaft.

[0010] In some embodiments, based on the completion of the pre-positioning, controlling the second positioning assembly to move along the preset axis toward the cross axis so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence includes:

[0011] Based on the completion of the pre-positioning, the second positioning assembly is controlled to move along the preset axis toward the cross axis at a first speed until the shaft head to be processed abuts against the first guiding bevel of the first clamping jaw and the second guiding bevel of the second clamping jaw at the same time; the first guiding bevel and the abutting plane intersect; and the second guiding bevel and the correction bevel intersect;

[0012] Based on the shaft head abutting the first guide inclined surface and the second guide inclined surface at the same time, controlling the distance between the first clamping claw and the second clamping claw to gradually increase until the shaft head is in a first abutting state;

[0013] Based on the shaft head being in the first abutting state, the distance between the first clamping claw and the second clamping claw is controlled to gradually decrease until the shaft head is in the second abutting state.

[0014] In some embodiments, based on the completion of the pre-positioning, controlling the second positioning assembly to move along the preset axis toward the cross axis so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence, further comprising:

[0015] Based on the shaft head abutting the first guide slope and the second guide slope at the same time, the moving speed of the second positioning assembly is controlled to gradually decrease with the first speed as the initial speed until the shaft head is in the first abutting state.

[0016] In some embodiments, based on the first positioning assembly clamping the shaft body, the second positioning assembly is separated from the cross shaft, comprising:

[0017] Based on the first positioning assembly clamping the shaft body, the second positioning assembly is controlled to move away from the cross shaft along the preset axis at a second speed until the second positioning assembly is disengaged from the cross shaft; wherein the second speed is less than the first speed.

[0018] In some embodiments, when the cross shaft abuts the first claw and the second claw at the same time, the abutting force of the first claw on the shaft head is controlled to be greater than the abutting force of the second claw on the shaft head; the first claw is located on the side of the cross shaft away from the positioning seat.

[0019] In a second aspect, the present invention provides a positioning device for a differential cross shaft, wherein the positioning device for a differential cross shaft is applied to the positioning method for a differential cross shaft according to any embodiment of the first aspect; the positioning device for a differential cross shaft comprises:

[0020] a first positioning assembly, comprising a positioning seat, a positioning pin, a pressure head, and a first driving unit; the positioning pin is fixedly connected to the positioning seat; the positioning seat and the pressure head are arranged opposite to each other; the positioning pin is located on a side of the positioning seat facing the pressure head; the first driving unit drives the pressure head to move toward or away from the positioning seat;

[0021] The second positioning assembly comprises a mounting seat, a first claw, a second claw and a second driving unit; the first claw and the second claw are respectively arranged to slide relative to the mounting seat; the sliding directions of the first claw and the second claw are parallel to the axis of the positioning pin; the second driving unit drives the first claw and the second claw to move relative to each other; the first claw comprises a first movable block; the first movable block has an abutment plane; the second claw comprises a second movable block; the second movable block has two correction inclined surfaces; the two correction inclined surfaces intersect; the correction inclined surfaces and the abutment plane are both parallel to the preset axis; the preset axis passes between the first claw and the second claw; the preset axis intersects perpendicularly with the axis of the positioning pin; the correction inclined surface intersects with the abutment plane.

[0022] In some embodiments, the first movable block has a first guiding inclined surface; the abutting plane intersects with the first guiding inclined surface; the end of the first guiding inclined surface close to the first positioning component is inclined in a direction away from the preset axis; the first guiding inclined surface is an inclined plane or a conical surface;

[0023] The second movable block has a second guiding inclined surface, which intersects with the correction inclined surface; the second guiding inclined surface is inclined toward a direction away from the preset axis at one end close to the first positioning component; the second guiding inclined surface is an inclined plane or a conical surface.

[0024] In some embodiments, the second driving unit includes an elastic part, a first sliding part and a second sliding part; the first sliding part and the second sliding part are both slidably connected to the mounting seat; the first sliding part and the second sliding part both slide in a direction parallel to the axis of the positioning pin; the elastic part is connected between the first sliding part and the second sliding part; under the action of the elastic force of the elastic part, the first sliding part and the second sliding part tend to approach each other.

[0025] In some embodiments, the first sliding portion includes a first slider, a second slider, and a first connecting rod; the first connecting rod is connected between the first slider and the second slider; the second slider is fixedly connected to the first claw; the second sliding portion includes a third slider, a fourth slider, and a second connecting rod; the second connecting rod is connected between the third slider and the fourth slider; the fourth slider is fixedly connected to the second claw;

[0026] The first slider, the second slider, the third slider, and the fourth slider are respectively slidably connected to the mounting seat; the sliding directions of the first slider, the second slider, the third slider, and the fourth slider are all parallel to the axial direction of the positioning pin; the distance between the first connecting rod and the second connecting rod gradually decreases in a direction away from the first clamping claw and the second clamping claw;

[0027] The elastic portion is connected between the first slider and the third slider; under the elastic action of the elastic portion, the first slider and the third slider tend to approach each other.

[0028] In some embodiments, the elastic portion includes a first elastic member and a second elastic member; one end of the first elastic member is connected to the mounting seat, and the other end is connected to the first slider; one end of the second elastic member is connected to the mounting seat, and the other end is connected to the third slider;

[0029] The included angle between the first connecting rod and the preset axis is smaller than the included angle between the second connecting rod and the preset axis; or the elastic coefficient of the first elastic member is greater than the elastic coefficient of the second elastic member.

[0030] In order to solve the problem of poor positioning accuracy caused by the difference in cutting edges of the outer circumferential surface of the shaft head of the cross shaft blank, the present invention has the following advantages:

[0031] By using the two design datums of the cross-axis, the positioning plane and the positioning hole, as the datum for pre-positioning, rather than the trimming of the blank, it is ensured that the initial datum for pre-positioning is not affected by the trimming difference. The angle between the shaft head to be processed and the preset axis is set to be less than the threshold value to avoid the second positioning component colliding with the shaft head due to excessive initial deviation of pre-positioning. By setting a first abutment state to partially constrain the shaft head, and then using a step-by-step abutment method to fully constrain the shaft head through the second abutment state, the shaft head is subjected to the force of the first clamping claw and the second clamping claw, and the posture is gradually adjusted to achieve precise positioning. This solves the problem of poor positioning accuracy caused by the trimming difference on the outer circumferential surface of the shaft head of the cross-axis blank. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of a method for positioning a differential cross shaft according to an embodiment of the related art is shown;

[0033] Figure 2 A schematic diagram of a blank trimming structure of a differential cross shaft according to another embodiment of the related art is shown;

[0034] Figure 3 A schematic diagram of a blank trimming structure of a differential cross shaft according to another embodiment of the related art is shown;

[0035] Figure 4 A schematic structural diagram of a first positioning assembly of a method for positioning a differential cross shaft according to an embodiment is shown;

[0036] Figure 5 Shown Figure 4 A front view of the first positioning assembly in FIG;

[0037] Figure 6 A schematic structural diagram of a second positioning assembly of a method for positioning a differential cross shaft according to an embodiment is shown;

[0038] Figure 7 A simplified schematic diagram showing a first abutment state of a positioning method for a differential cross shaft according to an embodiment is shown;

[0039] Figure 8 A simplified schematic diagram showing a second abutment state of a positioning method for a differential cross shaft according to an embodiment;

[0040] Figure 9 A schematic structural diagram of a second positioning assembly of a method for positioning a differential cross shaft according to an embodiment is shown;

[0041] Figure 10 A schematic structural diagram of a positioning device for a differential cross shaft according to an embodiment is shown;

[0042] Figure 11A cross-sectional view showing a second positioning assembly of a positioning device for a differential cross shaft according to an embodiment;

[0043] Figure 12 A cross-sectional view showing a second positioning assembly of a positioning device for a differential cross shaft according to another embodiment;

[0044] Figure 13 A schematic structural diagram of a cross shaft according to an embodiment is shown.

[0045] Figure numerals: 10 first positioning assembly; 11 positioning seat; 12 positioning pin; 13 pressure head; 20 second positioning assembly; 21 mounting seat; 22 first clamping claw; 221 first movable block; 222 abutting plane; 223 first guide slope; 23 second clamping claw; 231 second movable block; 232 correction slope; 233 second guide slope; 24 second driving unit; 241 elastic part; 2411 first elastic member; 2412 second elastic member; 242 first sliding part; 2421 first slider; 2422 second slider; 2423 first connecting rod; 243 second sliding part; 2431 third slider; 2432 fourth slider; 2433 second connecting rod; 30 cross shaft; 31 shaft body; 32 shaft head; 33 positioning plane; 34 positioning hole; 40 positioning measuring rod. DETAILED DESCRIPTION

[0046] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the present disclosure, rather than to imply any limitation on the scope of the present disclosure.

[0047] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment." The term "another embodiment" is to be interpreted as "at least one other embodiment." Terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "vertical," "horizontal," "transverse," and "longitudinal" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily intended to better describe the present application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationships. For example, the term "on" may, in certain circumstances, be used to indicate a dependency or connection relationship. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. Furthermore, the terms "installed," "disposed," "provided with," "connected," and "connected" are to be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise specified, "plurality" means two or more.

[0048] The differential is a core component in an automotive transmission system, and planetary gear differentials are one of the most common types. They consist of a differential case, a cross shaft 30, planetary gears, and side gears. The cross shaft 30 typically consists of a shaft body 31 and four spindle heads 32 extending outward from the shaft body 31 in four directions. Before machining the outer surface of the cross shaft 30 blank and drilling the center holes in the spindle heads 32, the cross shaft 30 blank must be positioned on the machining machine.

[0049] like Figure 1 As shown, in the related art, a positioning rod 40 is usually installed on the clamping device of the machine tool, and the outer circle of the shaft head 32 to be processed is pressed against the positioning rod 40 to position the angle, ensuring that the shaft head 32 to be processed is parallel to the positioning rod 40, thereby ensuring that the processing feed direction is consistent with the axial direction of the shaft head 32. However, this positioning method has the following problems:

[0050] like Figure 2 As shown, the lower die is a fixed die and the upper die is a movable die. During the forging process, there will be an offset each time the die is closed, and the offset is not fixed each time, resulting in the difference in the trimming amount of each blank shaft head 32 at the parting surface. Due to the difference in trimming on both sides of the same blank, when the two end faces of the shaft body 31 are used as positioning surfaces, the angles of the fixed position measuring rod when it is fitted with the outer circle of the shaft head 32 will also be inconsistent. Figure 3 As shown, the machining of both sides of the shaft head 32 is uneven, resulting in waste. The difference in trimming of different cross shaft 30 blanks and the different manual material placement techniques will cause the positioning of the cross shaft 30 to be processed on the clamping device of the machine tool to deviate, thereby reducing the processing accuracy of the product.

[0051] Example 1:

[0052] In order to solve the problem of poor positioning accuracy caused by the difference in cutting edges of the outer circumferential surface of the shaft head 32 of the cross shaft 30 blank, this embodiment discloses a positioning method for the differential cross shaft 30.

[0053] In this embodiment, if Figure 4 and Figure 5 As shown, the first positioning assembly 10 includes a positioning seat 11, a positioning pin 12 and a pressure head 13, and the positioning pin 12 is fixedly connected to the positioning seat 11. Figure 13 As shown, the cross shaft 30 includes an integrally formed shaft body 31 and four shaft heads 32 . Both end faces of the shaft body 31 are positioning planes 33 , and positioning holes 34 are located on the shaft body 31 .

[0054] Using one of the positioning flats 33 and the positioning hole 34 of the cross shaft 30 as a reference, the cross shaft 30 is pre-positioned in the first positioning assembly 10. When pre-positioning is complete, the positioning flats 33 align with the positioning seat 11, the positioning hole 34 engages with the positioning pin 12, and the angle between the shaft head 32 to be machined and the preset axis is less than a threshold. The press head 13 can move within a certain range along the axis of the positioning seat 11 and is positioned away from the positioning seat 11 before pre-positioning.

[0055] By aligning the shape and size of the locating pin 12 and the locating seat 11 with the locating hole 34, the structural characteristics of the locating hole 34 on the cross shaft 30 are combined to pre-position the cross shaft 30 while simplifying the structural design of the first positioning assembly 10. By using the two end faces of the shaft body 31 as the positioning planes 33, and then using the locating hole 34 on the shaft body 31 as the reference, the pre-positioning process uses the design reference of the cross shaft 30, rather than the edge of the blank, which is prone to dimensional fluctuations after processing. This ensures that the initial reference for pre-positioning is not affected by trimming differences. This makes the pre-positioning reference more stable and solves the problem of poor positioning accuracy caused by trimming differences on the outer circumferential surface of the shaft head 32 of the cross shaft 30 blank.

[0056] Upon completion of pre-positioning, the second positioning assembly 20 is controlled to move along the preset axis toward the cross shaft 30, so that the shaft head 32 to be processed is sequentially placed in the first abutment state and the second abutment state. After the above movement is completed, the shaft head 32 and the second positioning assembly 20 have sufficient contact range to ensure the accuracy of precise positioning. By setting the angle between the shaft head 32 to be processed of the cross shaft 30 and the preset axis to be less than a threshold, it is possible to avoid collision between the second positioning assembly 20 and the shaft head 32 when the pre-positioning deviation is large.

[0057] like Figure 6 As shown, the second positioning assembly 20 includes a first claw 22 and a second claw 23. The first claw 22 has a first face 222, and the second claw 23 has two intersecting correction slopes 232, wherein the abutting plane 222 intersects the correction slopes 232.

[0058] like Figure 7 As shown, when the shaft head 32 is in the first contact state, the contact plane 222 and one of the correction inclined surfaces 232 contact the shaft head 32 at the same time. Figure 8 As shown, when the shaft head 32 is in the second abutment state, the abutment plane 222 and the two correction bevels 232 simultaneously abut against the shaft head 32, and the axis of the shaft head 32 coincides with the predetermined axis. The first and second clamping jaws 22, 23 are controlled to cause the shaft head 32 to transition from the first abutment state to the second abutment state. It should be understood that during the transition from the first abutment state to the second abutment state, the first and second clamping jaws 22, 23 exert a clamping force on the shaft head 32.

[0059] When the shaft head 32 to be processed is in the second abutment state, the second positioning assembly 20 is controlled to stop moving. When the second positioning assembly 20 is in a stationary state, the pressing head 13 is controlled to cooperate with the positioning seat 11 to clamp the shaft body 31 of the cross shaft 30. When the first positioning assembly 10 clamps the shaft body 31, the second positioning assembly 20 is separated from the cross shaft 30, thus completing the final positioning.

[0060] Before precise positioning begins, the shaft head 32 is offset from the preset axis and can only be in the first abutment state. After being corrected to the second abutment state, precise positioning is achieved. The clamping timing and driving method of the first and second jaws 22 and 23 are related to the distance the second positioning assembly 20 moves along the preset axis.

[0061] By gradually bringing the shaft head 32 into contact with the abutment plane 222 and the correction bevel 232 of the second positioning assembly 20, the angle of the shaft head 32 is automatically adjusted by utilizing the constraint relationship of the mechanical structure until its axis coincides with the preset axis, thereby eliminating the error caused by manual positioning and achieving higher positioning accuracy.

[0062] Preferably, the fixed connection between the locating pin 12 and the locating seat 11 can be configured as an integral part. This can improve the strength while avoiding possible machining tolerances or assembly errors in the split fixed connection between the locating pin 12 and the locating seat 11.

[0063] Further, if Figure 10 As shown, based on the completion of the pre-positioning, the second positioning assembly 20 is controlled to move along the preset axis toward the cross shaft 30 so that the shaft head 32 to be processed is in the first abutment state and the second abutment state in sequence, including:

[0064] Based on the completion of the pre-positioning, the second positioning assembly 20 is controlled to move along the preset axis toward the cross shaft 30 at a first speed until the shaft head 32 to be processed abuts against the first guide slope 223 of the first jaw 22 and the second guide slope 233 of the second jaw 23 at the same time. Figure 6 As shown, the first guide slope 223 and the abutment plane 222 intersect. Figure 9 As shown, the second guiding slope 233 and the correction slope 232 intersect.

[0065] Based on the shaft head 32 abutting the first guide inclined surface 223 and the second guide inclined surface 233 at the same time, the distance between the first clamping claw 22 and the second clamping claw 23 is controlled to gradually increase until the shaft head 32 is in the first abutting state;

[0066] Based on the shaft head 32 being in the first abutting state, the distance between the first clamping claw 22 and the second clamping claw 23 is controlled to gradually decrease until the shaft head 32 is in the second abutting state.

[0067] By setting the shaft head 32 to abut against the first guiding slope 223 and the second guiding slope 233 , the shaft head 32 and the first guiding slope 223 and the second guiding slope 233 can slide relative to each other when the second positioning assembly 20 moves along the preset axis toward the cross shaft 30 .

[0068] Further, if Figure 10As shown, based on the completion of the pre-positioning, the second positioning assembly 20 is controlled to move along the preset axis toward the cross shaft 30 so that the shaft head 32 to be processed is in the first abutment state and the second abutment state in sequence, and further includes:

[0069] Based on the shaft head 32 abutting the first guiding inclined surface 223 and the second guiding inclined surface 233 at the same time, the moving speed of the second positioning assembly 20 is controlled to gradually decrease with the first speed as the initial speed until the shaft head 32 is in the first abutting state.

[0070] By gradually decreasing the moving speed of the second positioning component 20 from the first speed as the initial speed, the relative sliding speed between the shaft head 32 and the first guide bevel 223 and the second guide bevel 233 can be reduced, thereby avoiding excessive frictional heat generation and thus damaging the second positioning component 20.

[0071] Further, if Figure 10 As shown, based on the first positioning assembly 10 clamping the shaft body 31, the second positioning assembly 20 is separated from the cross shaft 30, including:

[0072] Based on the first positioning assembly 10 clamping the shaft body 31 , the second positioning assembly 20 is controlled to move along the preset axis away from the cross shaft 30 at a second speed until the second positioning assembly 20 is separated from the cross shaft 30 ; wherein the second speed is lower than the first speed.

[0073] This allows the second positioning assembly 20 to separate from the cross shaft 30 at a speed slower than the speed at which the second positioning assembly 20 moves along the predetermined axis toward the cross shaft 30, thereby preventing the second positioning assembly 20 from sliding rapidly relative to the shaft head 32 during the separation process. This reduces frictional wear on the second positioning assembly 20 and prevents the shaft head 32 from deviating due to friction.

[0074] Further, if Figure 10 As shown, when the cross shaft 30 abuts the first claw 22 and the second claw 23 at the same time, the abutting force of the first claw 22 on the shaft head 32 is controlled to be greater than the abutting force of the second claw 23 on the shaft head 32. The first claw 22 is located on the side of the cross shaft 30 away from the positioning seat 11.

[0075] When pre-positioning is complete, the positioning plane 33 is aligned with the positioning seat 11, and the positioning hole 34 is plugged into the positioning pin 12. When pre-positioning is complete, the pressure head 13 is a certain distance away from the positioning seat 11. By controlling the abutment force of the first claw 22 on the shaft head 32 to be greater than the abutment force of the second claw 23 on the shaft head 32, the cross shaft 30 tends to be pressed toward the positioning seat 11, preventing the cross shaft 30 from slightly moving away from the positioning seat 11.

[0076] Example 2:

[0077] This embodiment discloses a positioning device for a differential cross shaft 30. In this embodiment, the positioning device for a differential cross shaft 30 is applied to any one of the positioning methods for a differential cross shaft 30 in the first embodiment.

[0078] Further, if Figure 10 As shown, the positioning device includes a first positioning assembly 10 and a second positioning assembly 20. The first positioning assembly 10 includes a positioning seat 11, a positioning pin 12, a pressure head 13 and a first drive unit. The positioning pin 12 is fixedly connected to the positioning seat 11, and the positioning seat 11 and the pressure head 13 are arranged opposite to each other, so that the cross shaft 30 can be pre-positioned after being placed on the positioning seat 11. The positioning pin 12 is located on the side of the positioning seat 11 facing the pressure head 13, and the first drive unit drives the pressure head 13 to move toward or away from the positioning seat 11. When the first drive unit controls the pressure head 13 to move away from the positioning seat 11, a certain distance exists between the pressure head 13 and the positioning seat 11, and the cross shaft 30 can be placed on the positioning seat 11, and the positioning pin 12 is plugged into the positioning hole 34. After the cross shaft 30 is accurately positioned on the positioning seat 11, the first drive unit controls the pressure head 13 to move toward the positioning seat 11, so that the cross shaft 30 can be stably pressed against the positioning seat 11.

[0079] The second positioning assembly 20 includes a mounting base 21, a first clamping jaw 22, a second clamping jaw 23, and a second drive unit 24. The first clamping jaw 22 and the second clamping jaw 23 are each arranged to slide relative to the mounting base 21. The sliding directions of the first clamping jaw 22 and the second clamping jaw 23 are both parallel to the axis of the positioning pin 12. The second drive unit 24 drives the first clamping jaw 22 and the second clamping jaw 23 to move relative to each other. This allows for precise control of the contact time between the first and second clamping jaws 22 and 23 and the magnitude of the clamping force on the cross shaft 30. The first clamping jaw 22 includes a first movable block 221 with an abutment plane 222. The second clamping jaw 23 includes a second movable block 231 with two intersecting correction bevels 232. The correction bevels 232 and the abutment plane 222 are both parallel to a predetermined axis, which runs between the first and second clamping jaws 22 and 23 and intersects perpendicularly with the axis of the positioning pin 12. The correction bevel 232 intersects with the abutment plane 222. In this way, after the second positioning assembly 20 moves along the preset axis toward the cross shaft 30, the shaft head 32 to be processed of the cross shaft 30, whose angle with the preset axis is less than a threshold, can smoothly enter the position between the first clamping jaw 22 and the second clamping jaw 23. Then, the second driving unit 24 drives the first clamping jaw 22 and the second clamping jaw 23 to move toward the preset axis, so that the shaft head 32 and the second positioning assembly 20 transition from the mutually disengaged state to the first abutment state and the second abutment state in sequence.

[0080] Further, if Figure 6As shown, the first movable block 221 has a first guiding slope 223, and the abutting plane 222 intersects the first guiding slope 223. The first guiding slope 223 is inclined away from the preset axis at one end close to the first positioning assembly 10. The first guiding slope 223 is an inclined plane or a conical surface.

[0081] The second movable block 231 has a second guide bevel 233 intersecting the correction bevel 232. The second guide bevel 233, located on the end closest to the first positioning assembly 10, is tilted away from the predetermined axis. The second guide bevel 233 is an inclined plane or a conical surface. This allows the shaft head 32 to slide relative to the first and second guide bevels 223 and 233 as the second positioning assembly 20 moves along the predetermined axis toward the cross shaft 30. This allows subsequent precise positioning to be achieved even when the shaft head 32 deviates slightly from the predetermined axis.

[0082] Further, if Figure 11 As shown, the second drive unit 24 includes an elastic portion 241, a first sliding portion 242, and a second sliding portion 243. The first sliding portion 242 and the second sliding portion 243 are both slidably connected to the mounting base 21; the first sliding portion 242 and the second sliding portion 243 both slide in a direction parallel to the axis of the positioning pin 12; and the sliding directions of the first claw 22 and the second claw 23 are both parallel to the axis of the positioning pin 12; the elastic portion 241 is connected between the first sliding portion 242 and the second sliding portion 243; under the elastic force of the elastic portion 241, the first sliding portion 242 and the second sliding portion 243 tend to move closer to each other. The first sliding portion 242 is connected to the first claw 22, and the second sliding portion 243 is connected to the second claw 23. After entering the first abutment state, the first claw 22 and the second claw 23 are abutted against the shaft head 32 located between them, causing them to move away from each other, exerting an elastic force on the elastic portion 241. Due to the elastic force of the elastic part 241, the first sliding part 242 and the second sliding part 243 tend to approach each other, so that the first sliding part 242 and the second sliding part 243 respectively drive the first claw 22 and the second claw 23 to move in a direction parallel to the axis of the positioning pin 12 toward each other, thereby realizing the action of the first claw 22 and the second claw 23 on the shaft head 32 in the first abutment state and the second abutment state.

[0083] Further, if Figure 11As shown, the first sliding portion 242 includes a first slider 2421, a second slider 2422, and a first connecting rod 2423. The first connecting rod 2423 is connected between the first slider 2421 and the second slider 2422; the second slider 2422 is fixedly connected to the first claw 22; the second sliding portion 243 includes a third slider 2431, a fourth slider 2432, and a second connecting rod 2433; the second connecting rod 2433 is connected between the third slider 2431 and the fourth slider 2432; the fourth slider 2432 is fixedly connected to the second claw 23.

[0084] The first slider 2421, the second slider 2422, the third slider 2431 and the fourth slider 2432 are respectively slidably connected to the mounting seat 21; the sliding directions of the first slider 2421, the second slider 2422, the third slider 2431 and the fourth slider 2432 are all parallel to the axial direction of the positioning pin 12; the distance between the first connecting rod 2423 and the second connecting rod 2433 gradually decreases in the direction away from the first claw 22 and the second claw 23.

[0085] The elastic portion 241 is connected between the first slider 2421 and the third slider 2431 . Under the elastic action of the elastic portion 241 , the first slider 2421 and the third slider 2431 tend to approach each other.

[0086] The distance between the first connecting rod 2423 and the second connecting rod 2433 is gradually reduced in the direction away from the first claw 22 and the second claw 23, so that the length of the elastic portion 241 can be reduced, reducing costs. In addition, the elastic force of the shorter elastic portion 241 is more controllable and the effective use time is longer.

[0087] Further, if Figure 12 As shown, the elastic portion 241 includes a first elastic member 2411 and a second elastic member 2412. One end of the first elastic member 2411 is connected to the mounting seat 21, and the other end is connected to the first slider 2421; one end of the second elastic member 2412 is connected to the mounting seat 21, and the other end is connected to the third slider 2431;

[0088] The angle between the first connecting rod 2423 and the preset axis is smaller than the angle between the second connecting rod 2433 and the preset axis; or the elastic coefficient of the first elastic member 2411 is greater than the elastic coefficient of the second elastic member 2412. This ensures that during the precise positioning process, the elastic force of the first elastic member 2411 is always greater than the elastic force of the second elastic member 2412. As a result, through the actions of the first slider 2421, the first connecting rod 2423, the second slider 2422, the third slider 2431, the second connecting rod 2433, and the fourth slider 2432, the abutting force of the first clamping claw 22 on the shaft head 32 is greater than the abutting force of the second clamping claw 23 on the shaft head 32.

[0089] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and that in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A method for positioning a differential cross shaft, characterized in that: The positioning method of the differential cross shaft includes: The cross shaft is pre-positioned in the first positioning assembly based on one of the positioning planes and the positioning hole of the cross shaft; wherein the cross shaft comprises an integrally formed shaft body and four shaft heads; both end faces of the shaft body are the positioning planes; the positioning hole is located on the shaft body; the first positioning assembly comprises a positioning seat, a positioning pin and a pressure head; the positioning pin is fixedly connected to the positioning seat; when the pre-positioning is completed, the positioning plane is in contact with the positioning seat, the positioning hole is plugged into the positioning pin, and the angle between the shaft head to be processed of the cross shaft and the preset axis is less than a threshold value; Based on the completion of the pre-positioning, the second positioning assembly is controlled to move along the preset axis toward the cross axis, so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence; wherein the second positioning assembly includes a first claw and a second claw; the first claw has an abutment plane; the second claw has two intersecting correction inclined surfaces; the abutment plane intersects with the correction inclined surfaces; when the shaft head is in the first abutment state, the abutment plane and one of the correction inclined surfaces abut against the shaft head at the same time; when the shaft head is in the second abutment state, the abutment plane and the two correction inclined surfaces abut against the shaft head at the same time, and the axis of the shaft head coincides with the preset axis; Based on the shaft head to be processed being in the second abutment state, controlling the second positioning assembly to stop moving; Based on the second positioning assembly being in a stationary state, controlling the pressing head to cooperate with the positioning seat to clamp the shaft body of the cross shaft; Based on the first positioning assembly clamping the shaft body, the second positioning assembly is separated from the cross shaft.

2. A method for positioning a differential cross shaft according to claim 1, characterized in that: Based on the completion of the pre-positioning, controlling the second positioning assembly to move along the preset axis toward the cross axis so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence, including: Based on the completion of the pre-positioning, the second positioning assembly is controlled to move along the preset axis toward the cross axis at a first speed until the shaft head to be processed abuts against the first guiding bevel of the first clamping jaw and the second guiding bevel of the second clamping jaw at the same time; the first guiding bevel and the abutting plane intersect; and the second guiding bevel and the correction bevel intersect; Based on the shaft head abutting the first guide inclined surface and the second guide inclined surface at the same time, controlling the distance between the first clamping claw and the second clamping claw to gradually increase until the shaft head is in a first abutting state; Based on the shaft head being in the first abutting state, the distance between the first clamping claw and the second clamping claw is controlled to gradually decrease until the shaft head is in the second abutting state.

3. A method for positioning a differential cross shaft according to claim 2, characterized in that: Based on the completion of the pre-positioning, controlling the second positioning assembly to move along the preset axis toward the cross axis so that the shaft head to be processed is in the first abutment state and the second abutment state in sequence, further comprising: Based on the shaft head abutting the first guide slope and the second guide slope at the same time, the moving speed of the second positioning assembly is controlled to gradually decrease with the first speed as the initial speed until the shaft head is in the first abutting state.

4. A method for positioning a differential cross shaft according to claim 3, characterized in that: Based on the first positioning assembly clamping the shaft body, the second positioning assembly is separated from the cross shaft, comprising: Based on the first positioning assembly clamping the shaft body, the second positioning assembly is controlled to move away from the cross shaft along the preset axis at a second speed until the second positioning assembly is disengaged from the cross shaft; wherein the second speed is less than the first speed.

5. The method for positioning a differential cross shaft according to claim 3, characterized in that: When the cross shaft abuts the first clamping claw and the second clamping claw at the same time, the abutting force of the first clamping claw on the shaft head is controlled to be greater than the abutting force of the second clamping claw on the shaft head; the first clamping claw is located on the side of the cross shaft away from the positioning seat.

6. A positioning device for a differential cross shaft, characterized in that: The positioning device of the differential cross shaft includes: a first positioning assembly, comprising a positioning seat, a positioning pin, a pressure head, and a first driving unit; the positioning pin is fixedly connected to the positioning seat; the positioning seat and the pressure head are arranged opposite to each other; the positioning pin is located on a side of the positioning seat facing the pressure head; the first driving unit drives the pressure head to move toward or away from the positioning seat; The second positioning assembly comprises a mounting seat, a first claw, a second claw and a second driving unit; the first claw and the second claw are respectively arranged to slide relative to the mounting seat; the sliding directions of the first claw and the second claw are parallel to the axis of the positioning pin; the second driving unit drives the first claw and the second claw to move relative to each other; the first claw comprises a first movable block; the first movable block has an abutment plane; the second claw comprises a second movable block; the second movable block has two correction inclined surfaces; the two correction inclined surfaces intersect; the correction inclined surfaces and the abutment plane are both parallel to the preset axis; the preset axis passes between the first claw and the second claw; the preset axis intersects perpendicularly with the axis of the positioning pin; the correction inclined surface intersects with the abutment plane.

7. The positioning device for a differential cross shaft according to claim 6, characterized in that: The first movable block has a first guiding inclined surface; the abutting plane intersects with the first guiding inclined surface; the end of the first guiding inclined surface close to the first positioning component is inclined in a direction away from the preset axis; the first guiding inclined surface is an inclined plane or a conical surface; The second movable block has a second guiding inclined surface, which intersects with the correction inclined surface; the second guiding inclined surface is inclined toward a direction away from the preset axis at one end close to the first positioning component; the second guiding inclined surface is an inclined plane or a conical surface.

8. The positioning device for a differential cross shaft according to claim 7, characterized in that: The second driving unit includes an elastic part, a first sliding part and a second sliding part; the first sliding part and the second sliding part are both slidably connected to the mounting seat; the first sliding part and the second sliding part both slide in a direction parallel to the axis of the positioning pin; the elastic part is connected between the first sliding part and the second sliding part; under the action of the elastic force of the elastic part, the first sliding part and the second sliding part tend to approach each other.

9. The positioning device for a differential cross shaft according to claim 8, characterized in that: The first sliding portion includes a first slider, a second slider, and a first connecting rod; the first connecting rod is connected between the first slider and the second slider; the second slider is fixedly connected to the first claw; the second sliding portion includes a third slider, a fourth slider, and a second connecting rod; the second connecting rod is connected between the third slider and the fourth slider; the fourth slider is fixedly connected to the second claw; The first slider, the second slider, the third slider, and the fourth slider are respectively slidably connected to the mounting seat; the sliding directions of the first slider, the second slider, the third slider, and the fourth slider are all parallel to the axial direction of the positioning pin; the distance between the first connecting rod and the second connecting rod gradually decreases in a direction away from the first clamping claw and the second clamping claw; The elastic portion is connected between the first slider and the third slider; under the elastic action of the elastic portion, the first slider and the third slider tend to approach each other.

10. The positioning device for a differential cross shaft according to claim 9, characterized in that: The elastic portion includes a first elastic member and a second elastic member; one end of the first elastic member is connected to the mounting seat, and the other end is connected to the first slider; one end of the second elastic member is connected to the mounting seat, and the other end is connected to the third slider; The included angle between the first connecting rod and the preset axis is smaller than the included angle between the second connecting rod and the preset axis; or the elastic coefficient of the first elastic member is greater than the elastic coefficient of the second elastic member.

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