Shift device and control method thereof

Abstract

The application provides a gear shifting device and a control method thereof, comprising a gear ring, a sliding block and a retaining ring are sleeved on the outer periphery of the gear ring, the retaining ring is arranged outside the sliding block, characterized in that: the retaining ring is fixedly arranged on the outer periphery of the gear ring, the sliding block is movably arranged on the outer periphery of the gear ring and can slide along the axial direction of the gear ring, and an elastic element is further connected between the sliding block and the retaining ring which are arranged adjacently; the gear shifting impact can be absorbed when the gear is shifted in, so that the driving torque of the gear shifting motor can be kept unchanged, and when the gear is engaged, the gear shifting motor can continue to rotate because the elastic element can be compressed, the energy is stored in the compressed elastic element, after the gear is engaged, the elastic element releases the energy quickly, and the engaging sleeve is pushed to complete the gear shifting process, the gear engaging impact in the gear shifting process is effectively reduced through the elastic element, the service life is prolonged, and the gear shifting process is stable.

Description

Technical Field

[0001] This invention relates to the technical field of mining vehicle transmissions, specifically to a shifting device and its control method. Background Technology

[0002] For automatic transmissions used in pure electric vehicles, the synchronizer is eliminated because the drive motor has high speed control precision and fast speed adjustment response. Instead, a coupling sleeve is used to achieve gear shifting. However, poor speed synchronization can cause shifting shock and reduce the life of components.

[0003] The automatic transmissions used in pure electric mining trucks have very high durability requirements, such as... Figure 1-2 As shown, both the engagement sleeve A and the engagement gear B adopt the end-face flat tooth C scheme, which can improve the strength of the components themselves. However, with the end-face flat tooth C scheme, tooth backing will occur in most cases during gear shifting, which will cause shifting impact. Therefore, it is necessary to accurately control the moving speed of the engagement sleeve to reduce shifting impact. In practice, this is achieved by controlling the output torque of the shifting motor. During gear shifting, the torque of the shifting motor must go through the process of "drive-brake-hold-drive-brake" and complete the above actions within 300ms. This places high demands on the hardware and software of the control system, and it is difficult to guarantee the consistency of the control effect.

[0004] Therefore, the shortcomings and deficiencies of the existing technology that uses face-mounted flat teeth to achieve gear shifting are as follows:

[0005] 1) While the flat teeth on the end face can improve the durability of the engagement sleeve and engagement gear, they also greatly increase the probability of tooth tipping. Tooth tipping causes gear shifting difficulties and NVH problems. In addition, long-term tooth tipping impact is also detrimental to the life of the gear shifting actuator.

[0006] 2) In order to reduce the damage caused by the top gear, the control process of the shift motor is complicated. On the one hand, the shifting time is longer, and on the other hand, the control process is complicated. Once it is disturbed by external factors, it is difficult to guarantee the consistency of the control effect. For example, when shifting gears, the wheel is impacted by the road surface, or the feedback signal of the shift fork position is disturbed, which will affect the control effect.

[0007] Therefore, there is an urgent need to propose a shifting device and its control method to solve the defects and shortcomings of the existing technology. Summary of the Invention

[0008] In order to overcome the defects and shortcomings of the existing technology, the present invention provides a gear shifting device and its control method.

[0009] The technical solution provided by this invention is as follows:

[0010] The beneficial effects of this invention compared to the prior art are as follows:

[0011] 1) This invention provides a gear shifting device and its control method. The gear shifting device includes an elastic element that can absorb the gear shifting impact during gear shifting, so the gear shifting motor can maintain a constant driving torque. When the gear is engaged, the gear shifting motor can continue to rotate because the elastic element is compressible, storing energy in the compressed elastic element. After the gear engagement is completed, the elastic element quickly releases energy, pushing the engagement sleeve to complete the gear shifting process. The elastic element effectively reduces the gear engagement impact during gear shifting, extends the service life, and ensures the stability of the gear shifting process.

[0012] 2) This invention provides a gear shifting device and its control method, which eliminates the multiple acceleration and deceleration processes of the gear shifting motor, thus shortening the gear shifting time.

[0013] 3) This invention provides a shifting device and its control method, in which the shifting motor maintains a constant driving torque, making the control of the shifting motor simpler and simplifying the control process. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the shift engagement sleeve and shift gear in the prior art.

[0015] Figure 2 This is a schematic diagram of the structure of a shift gear in the prior art.

[0016] Figure 3 An exploded view of the gear shifting device provided by the present invention.

[0017] Figure 4 This is a cross-sectional view of the gear shifting device provided by the present invention.

[0018] Figure 5 A flowchart illustrating the steps of the shift control method provided by the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] [First Embodiment]

[0023] like Figure 3-4 The diagram shows a gear shifting device according to a first embodiment of the present invention, comprising a gear ring 1, a slider 2 and a retaining ring 4 sleeved on the outer periphery of the gear ring 1, the retaining ring 4 being disposed on the outer side of the slider 2 and fixedly disposed on the outer periphery of the gear ring 1, the slider 2 being movably disposed on the outer periphery of the gear ring 1 and being able to slide along the axial direction of the gear ring 1, and an elastic element 3 being connected between adjacent slider 2 and retaining ring 4. By providing the elastic element 3, on the one hand, the impact of the top tooth during the gear shifting process can be effectively reduced, the service life can be extended, and the gear shifting process can be ensured to be stable; on the other hand, the energy stored in the elastic element during the compression of the top tooth can help push the engaging sleeve to complete the gear shifting process, thereby realizing rapid gear shifting.

[0024] like Figure 4 As shown, in this embodiment, a positioning part 11 is provided protruding from the middle of the outer edge of the gear ring 1. A receiving part 12 is formed between the outer wall of the positioning part 11 and the outer top wall of the gear ring 1. The slider 2 is located at the receiving part 12 and is positioned in the axial direction by the positioning part 11.

[0025] like Figure 4 As shown, in this embodiment, the cross-section of the slider 2 is set to L-shape. The radial outer edge 21 of the slider 2 is engaged with the outer wall of the positioning part 11, and the axial outer edge 22 of the slider 2 is engaged with the outer top wall of the gear ring 1. During the shifting process, the radial outer edge 21 of the slider 2 can be pushed to slide along the plane where the axial outer edge 22 is located, thereby applying compressive force to the elastic element 3.

[0026] In this embodiment, the elastic element 3 is installed inside the shifting device. The elastic element 3 can also be installed in the shifting drum as needed. In this embodiment, the elastic element 3 is a wave spring. The main performance parameters of the wave spring include preload and maximum compression stroke.

[0027] The preload of the wave spring must meet the following requirements:

[0028] Fshift < Fpre < Fshock

[0029] in,

[0030] Fshift is the thrust required to shift gears;

[0031] Fpre is the preload force of the wave spring;

[0032] Fshock is the impact force when the tooth tip is engaged.

[0033] Fpre needs to be set slightly larger than the thrust Fshift required for normal shifting to ensure that the wave spring does not deform when there is no impact from a counter-tooth, and the engagement sleeve can respond quickly to the thrust of the shift fork. Conversely, Fpre should be set smaller than the impact force Fshock when a counter-tooth occurs, so that when a counter-tooth occurs, the impact force Fshock will be much greater than Fpre, compressing the wave spring to absorb the impact. In this embodiment, the thrust Fshift required for shifting can be determined first through dynamic simulation of the shifting mechanism, and then corrected through bench testing.

[0034] Existing shifting devices lack elastic elements. To reduce shifting impact, the torque of the shifting motor must be controlled in real time. Furthermore, the shifting motor stalls during gear engagement, and restarts from the stalled state to accelerate after engagement, completing the shift. In this embodiment, however, a shifting device with an elastic element is used. The wave spring element absorbs the shifting impact, allowing the shifting motor to maintain a constant drive torque. During gear engagement, the compressible wave spring allows the shifting motor to continue rotating, storing energy in the compressed spring. After engagement, the wave spring quickly releases its energy, pushing the engagement sleeve to complete the shift.

[0035] In this embodiment, another performance parameter of the wave spring, namely the maximum compression stroke Smax, satisfies:

[0036] S max >S fox

[0037] in,

[0038] Smax is the maximum compression stroke of the wave spring;

[0039] Sfox is the shift fork displacement caused by the continuous rotation of the shift motor during the gear shifting process.

[0040] This is to ensure that the shifting motor does not stall.

[0041] The relationship between the shift fork displacement Sfox and the shift drum rotation angle αdrum is a complex function, but during gear shifting, the relationship is linear, namely:

[0042] S fox =k×α drum

[0043] k is a coefficient.

[0044] αdrum is the rotation angle of the shift drum;

[0045] When shifting gears, the rotation angle αdrum of the shift drum is related to the speed nshift of the shift motor, the worm gear transmission ratio i, and the running time t, specifically:

[0046]

[0047] nshift is the speed of the shift motor;

[0048] i is the worm gear transmission ratio;

[0049] t is the time for the gear to be engaged during the gear shifting process;

[0050] The time t for the top tooth during the gear shifting process depends on the number of teeth z of the engagement sleeve and the speed difference Δn between the engagement sleeve and the engagement tooth during gear shifting.

[0051]

[0052] Δn is the speed difference between the engagement sleeve and the engagement teeth when shifting gears;

[0053] Z represents the number of teeth on the engagement sleeve.

[0054] Since the shift motor does not undergo multiple acceleration and deceleration processes during gear shifting, and the driving torque of the shift motor remains constant during gear shifting, the control of the shift motor becomes simpler. There is no stalling state, which can shorten the gear shifting time.

[0055] like Figure 3 As shown, in this embodiment, the inner edge of the retaining ring 4 is provided with a limiting groove 41 that cooperates with the upper limit part 23 of the outer edge of the slider 2, so as to fix the internal elastic element 3 while the retaining ring 4 and the slider 2 move synchronously. The inner edge of the retaining ring 4 is also provided with a positioning groove 42 for tooling assembly.

[0056] [Second Embodiment]

[0057] like Figure 5The diagram illustrates a control method for a gear shifting device according to a second embodiment of the present invention, comprising the following steps:

[0058] 1) Collect vehicle command data to determine if there is an upshift command among them;

[0059] 2) Determine if an upshift command exists: If the command exists, proceed to step 3); otherwise, return to step 2).

[0060] 3) The shift motor starts with high torque. Because there is an elastic element in the shift device, the shift motor does not have multiple acceleration and deceleration processes during the shifting process. The driving torque of the shift motor remains unchanged during the shifting process. Therefore, the control of the shift motor becomes simpler. There is no stall state, which can shorten the shifting time.

[0061] 4) Check the position of the shift fork;

[0062] 5) Determine if the sliding sleeve has reached the gear engagement position: if it has, proceed to step 6); otherwise, return to step 5.

[0063] 6) The motor brakes and stops during gear shifting.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A gear shifting device, comprising a gear ring (1), a slider (2) and a retaining ring (4) sleeved on the outer periphery of the gear ring (1), the retaining ring (4) being disposed on the outer side of the slider (2), characterized in that: The retaining ring (4) is fixedly disposed on the outer periphery of the toothed ring (1), the slider (2) is movably disposed on the outer periphery of the toothed ring (1) and can slide along the axial direction of the toothed ring (1), and an elastic element (3) is also connected between the adjacent slider (2) and the retaining ring (4). The elastic element (3) is selected as a wave spring; The maximum compression stroke Smax of the wave spring satisfies: ； in, Smax is the maximum compression stroke of the wave spring; Sfox is the shift fork displacement caused by the continuous rotation of the shift motor during the gear shifting process. ； k is a coefficient. αdrum is the rotation angle of the shift drum; When shifting gears ； nshift is the speed of the shift motor; i is the worm gear transmission ratio; t is the time for the gear to be engaged during the gear shifting process; ； Δn is the speed difference between the engagement sleeve and the engagement teeth when shifting gears; Z represents the number of teeth on the engagement sleeve.

2. The gear shifting device according to claim 1, characterized in that: A positioning part (11) is provided in the middle of the outer edge of the toothed ring (1), and a receiving part (12) is formed between the outer wall of the positioning part (11) and the outer top wall of the toothed ring (1).

3. A gear shifting device according to claim 2, characterized in that: The cross section of the slider (2) is set to L-shape. The radial outer edge (21) of the slider (2) is engaged with the outer wall of the positioning part (11), and the axial outer edge (22) of the slider (2) is engaged with the outer top wall of the gear ring (1).

4. A gear shifting device according to claim 1, characterized in that: The preload of the wave spring satisfies: Fshift < Fpre < Fshock in, Fshift is the thrust required to shift gears; Fpre is the preload force of the wave spring; Fshock is the impact force when the tooth tip is engaged.

5. A gear shifting device according to claim 4, characterized in that: The thrust Fshift required for shifting gears is first determined by dynamic simulation of the shifting mechanism, and then corrected by bench testing.

6. A gear shifting device according to claim 1, characterized in that: During gear shifting, the driving torque of the shifting motor remains constant.

7. A gear shifting device according to claim 1, characterized in that: The inner edge of the retaining ring (4) is provided with a limiting groove (41) that cooperates with the upper limit part (23) of the outer edge of the slider (2), and the inner edge of the retaining ring (4) is also provided with a positioning groove (42).

8. A control method for a gear shifting device according to any one of claims 1-7, characterized in that: Includes the following steps: 1) Collect vehicle command data; 2) Determine if an upshift command exists: if the command exists, proceed to step 3; otherwise, return to step 2. 3) The high-torque start-up of the shift motor 4) Check the position of the shift fork; 5) Determine if the sliding sleeve has reached the gear engagement position: if it has, proceed to step 6; otherwise, return to step 5. 6) The shift motor brakes and stops.

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