Parking mechanism

Abstract

The invention discloses a parking mechanism which comprises a parking motor, a lead screw shaft, a lead screw nut, a parking cam, an elastic piece, a pawl shaft, a parking pawl and a parking ratchet wheel. The parking motor is connected with the lead screw shaft so as to drive the lead screw shaft to rotate forwards and backwards. The lead screw shaft is sequentially sleeved with a lead screw nut, a parking cam and an elastic piece. The parking pawl is rotatably installed between the lead screw shaft and the parking ratchet wheel through a pawl shaft, and the lower end of the parking pawl is provided with a force application part extending towards the lead screw shaft so that the elastic piece can be extruded between the parking cam and the force application part. The upper end of the parking pawl is provided with a pawl part extending towards the parking ratchet wheel, and the other side, away from the pawl part, of the upper end of the parking pawl is provided with a pawl jacking part making contact with the parking cam. And a convex part and a concave part are arranged on the parking cam. The device has the advantages of being simple and compact in structure, convenient and flexible to operate, small in occupied space, easy to arrange and maintain and low in manufacturing and maintenance cost.

Description

Technical Field

[0001] This invention relates primarily to the field of automotive equipment technology, and more particularly to a parking mechanism. Background Technology

[0002] Currently, electric parking mechanisms on the market connect a drive motor to a reduction gear, which in turn drives a cam-shaped drive element or cylindrical roller to rotate the pawl. This causes the parking pawl to engage with the parking ratchet, achieving parking braking. The cam or cylindrical roller needs to be connected to a preloaded spring to store elastic potential energy during the parking process and to provide timely rebound to reduce impact force in the event of a high-speed collision between the parking ratchet and the parking pawl. The parking ratchet needs a return spring to assist the pawl in disengaging from the ratchet groove and to maintain pawl stability while the vehicle is in motion. The main technical problems are as follows: First, in existing electronic parking mechanisms, the cam and parking pawl use sliding friction, which causes the parking ratchet to wear easily, resulting in a relatively large parking force and potential parking difficulties later on.

[0003] Secondly, existing electronic parking mechanisms all contain two springs, namely a preload spring and a return spring, which are not only complex in structure and high in cost, but also occupy a lot of space and are not easy to arrange and maintain.

[0004] Third, existing electronic parking mechanisms generally use gear and rack, worm gear, and other similar mechanisms. These are relatively expensive and bulky.

[0005] Fourth, existing electronic parking mechanisms generally lack a manual unlocking function. In case of special circumstances, the inability to manually unlock the vehicle makes operation inconvenient and hinders rescue efforts. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a car parking mechanism that is simple and compact in structure, convenient and flexible in operation, occupies little space, is easy to arrange and maintain, and has low manufacturing and maintenance costs.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A parking mechanism includes a parking motor, a lead screw shaft, a lead screw nut, a parking cam, an elastic element, a pawl shaft, a parking pawl, and a parking ratchet. The parking motor and the lead screw shaft are connected to drive the lead screw shaft to rotate in both directions. The lead screw shaft is sequentially fitted with the lead screw nut, the parking cam, and the elastic element. The parking pawl is rotatably mounted between the lead screw shaft and the parking ratchet via a pawl shaft. The lower end of the parking pawl has a force-applying portion extending toward the lead screw shaft, which causes the elastic element to be pressed between the parking cam and the force-applying portion. The upper end of the parking pawl has a pawl portion extending toward the parking ratchet, and the other side of the upper end away from the pawl portion has a top pawl portion that contacts the parking cam. The parking cam has a protrusion and a recess. The protrusion is used to press against the top pawl portion during parking operations to engage the pawl portion with the parking ratchet. The recess is used to accommodate the top pawl portion during non-parking operations to disengage the pawl portion from the parking ratchet.

[0008] As a further improvement to the above technical solution: The top pawl is provided with a rotatable rolling element, which contacts the parking cam to buffer the thrust of the parking cam on the parking pawl and reduce wear on the parking pawl.

[0009] The rolling element is a cylindrical roller.

[0010] The protrusion of the parking cam includes a cylindrical body, and the recess includes a conical body connected to the protrusion.

[0011] Above the recessed portion, a first cylindrical portion is provided for abutting against the lead screw nut above. The diameter of the first cylindrical portion is smaller than the diameter of the protrusion so as not to hinder the movement of the top claw portion.

[0012] Below the protrusion, there is a second cylindrical portion, which has a receiving space for the upper part of the elastic member to extend into it to provide limiting protection for the elastic member.

[0013] The force-applying part is fork-shaped to allow the lead screw shaft to move through the force-applying part, and the parking pawl also has a hollow part between the upper and lower ends to reduce weight.

[0014] The lead screw shaft is a trapezoidal lead screw.

[0015] The pawl is provided with a guide ramp at the contact surface with the parking ratchet to facilitate engagement or disengagement between the pawl and the parking ratchet.

[0016] One end of the parking motor drive shaft is connected to the lead screw nut, and the other end of the parking motor drive shaft protrudes from the top cover of the parking motor to facilitate manual parking by manually turning the drive shaft.

[0017] Compared with the prior art, the advantages of the present invention are as follows: Firstly, the parking mechanism of this invention has a simple and compact structure, occupies little space, and is easy to operate and maintain. Excellent parking performance can be achieved by utilizing a parking motor, lead screw shaft, lead screw nut, parking cam, elastic element, pawl shaft, parking pawl, and parking ratchet that work together.

[0018] Secondly, the parking mechanism of the present invention, through a special structural design, uses an elastic element to replace the preload spring and return spring in the prior art, which reduces the number of parts, greatly improves the reliability of the parking mechanism, and significantly reduces manufacturing and maintenance costs.

[0019] Third, the parking mechanism of the present invention adopts a reduction mechanism that uses a lead screw shaft and a lead screw nut to replace the traditional gear rack, worm gear and other mechanisms. In particular, as described below, when the lead screw shaft adopts a trapezoidal lead screw with a one-way self-locking function, the cost is lower, the mechanism size is smaller, and it is easier to arrange. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural principle diagram of the parking mechanism of the present invention.

[0021] Figure 2 This is a schematic diagram of the structural principle of the parking mechanism of the present invention in the P gear neutral state.

[0022] Figure 3 This is a schematic diagram of the structural principle of the parking mechanism of the present invention during the parking process in P gear.

[0023] Figure 4 This is a schematic diagram of the structural principle of the parking mechanism of the present invention when parking in P gear is completed.

[0024] Figure 5 This is a top view schematic diagram of the parking mechanism of the present invention.

[0025] The labels in the diagram represent: 1. Parking motor; 2. Lead screw shaft; 3. Lead screw nut; 4. Parking cam; 41. Protrusion; 42. Recess; 43. First cylindrical part; 44. Second cylindrical part; 5. Elastic element; 6. Pawl shaft; 7. Parking pawl; 71. Force application part; 72. Pawl part; 73. Top pawl part; 74. Rolling element; 75. Hollowed-out part; 8. Parking ratchet. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "assembly," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] like Figures 1 to 5As shown, the parking mechanism of this embodiment includes a parking motor 1, a lead screw shaft 2, a lead screw nut 3, a parking cam 4, an elastic element 5, a pawl shaft 6, a parking pawl 7, and a parking ratchet 8. The parking motor 1 and the lead screw shaft 2 are connected to drive the lead screw shaft 2 to rotate in both directions. The lead screw shaft 2 is sequentially fitted with the lead screw nut 3, the parking cam 4, and the elastic element 5. The parking pawl 7 is rotatably mounted between the lead screw shaft 2 and the parking ratchet 8 via the pawl shaft 6. The lower end of the parking pawl 7 is provided with a force-applying part 71 extending toward the lead screw shaft 2 to... The elastic element 5 is pressed between the parking cam 4 and the force-applying part 71. The upper end of the parking pawl 7 is provided with a pawl part 72 extending toward the parking ratchet 8, and the other side of the upper end away from the pawl part 72 is provided with a top pawl part 73 that contacts the parking cam 4. The parking cam 4 is provided with a protrusion 41 and a recess 42. The protrusion 41 is used to press against the top pawl part 73 during parking operations to make the pawl part 72 engage with the parking ratchet 8. The recess 42 is used to accommodate the top pawl part 73 during non-parking operations to make the pawl part 72 disengage from the parking ratchet 8. In this embodiment, as shown in the figure, the upper part of the lead screw shaft 2 is provided with external threads for threaded engagement with the lead screw nut 3. The lower part of the lead screw shaft 2 is not provided with external threads, which facilitates smoother up-and-down sliding of the parking cam 4. Of course, in other embodiments, the lead screw shaft 2 can be provided entirely with external threads, and the through hole of the parking cam 4 can be large enough to move up and down along the lead screw shaft 2. All of these should fall within the protection scope of this invention. In this embodiment, as shown in the figure, the elastic element 5 is a helical spring sleeved on the lead screw shaft 2. The bottom of the parking motor 1 is also provided with a mounting plate, which has multiple fixing holes for fixing the parking motor 1. The specific implementation principle is as follows: like Figure 2 As shown, this is the P gear neutral position. At this time, the elastic element 5 is in a compressed state, that is, the elastic element 5 is squeezed between the parking cam 4 and the force application part 71. Under the thrust of the elastic element 5, the left top pawl part 73 of the parking pawl 7 is tightly attached to the recess 42 of the parking cam 4, and the right pawl part 72 of the parking pawl 7 is disengaged from the parking ratchet 8, allowing the parking ratchet 8 to rotate freely. The screw nut 3 is tightly attached to the upper part of the parking cam 4, and at this time the screw nut 3 is in a locked state, restricting the upward movement of the parking cam 4. The compressive thrust of the elastic element 5 also restricts the downward movement of the parking cam 4.

[0031] like Figure 3 , Figure 4The diagram shows the parking process in P gear. When parking in P gear, the parking motor 1 rotates forward, driving the lead screw shaft 2, which is fixed to the parking motor 1, to rotate forward as well, causing the lead screw nut 3 to move upward. Because the elastic element 5 is in a compressed state, the parking cam 4 moves upward under the thrust of the elastic element 5, causing the parking pawl 7 to rotate clockwise around the pawl shaft 6. At this time, the left pawl portion 73 on the parking pawl 7 gradually disengages from the recessed portion 42, and under the squeezing action of the protruding portion 41, the right pawl portion 72 of the parking pawl 7 gradually moves towards the right parking ratchet 8, as shown. Figure 3 The state shown clearly shows a difference compared to Figure 2 The pawl 72 has gradually moved toward the parking ratchet 8 on the right side.

[0032] It should be noted that at this point, if the pawl portion 72 of the parking pawl 7 contacts the tooth tip of the parking ratchet 9, the parking cam 4 cannot move upward further, and the elastic element 5 is still in a compressed, energy-storing state. However, once the parking ratchet 9 rotates, the parking cam 4 will continue to move upward under the push of the elastic element 5. Under the squeezing motion of the protrusion 41, the pawl portion 72 on the right side of the parking pawl 7 engages with the parking ratchet 9, the parking ratchet 8 can no longer rotate freely, the parking motor 1 stops driving, and the parking process is completed. Figure 4 The parking position is shown in the diagram. At this time, the vehicle is in Park (P) gear, and spring 5 is compressed (less than in neutral). The left pawl 73 of the parking pawl 7 is pressed against the protrusion 41 of the parking cam 4, and the right pawl 72 of the parking pawl 7 is engaged with the right parking ratchet 9, restricting the rotation of the parking ratchet 9. The screw nut 3 is pressed against the upper part of the parking cam 4 and is locked, restricting the upward movement of the parking cam 4. The compressive force of the elastic element 5 also restricts the downward movement of the parking cam 4.

[0033] When disengaging from P gear, the parking motor 1 rotates in the reverse direction, causing the lead screw shaft 2, which is fixed to the parking motor 1, to rotate in the reverse direction as well, thus moving the lead screw nut 3 downward. The lead screw nut 3 pushes the parking cam 4 downward as well, further compressing the elastic element 5. The elastic element 5 then presses downward against the force-applying part 71 of the parking ratchet 9. At this time, the downward-moving parking cam 4 causes the protrusion 41 to gradually disengage from the pawl 73, and the pawl 73 gradually retracts into the recess 42. That is, under the combined drive of the parking cam 4 and the elastic element 5, the parking pawl 7 gradually rotates counterclockwise around the pawl shaft 6. Finally, the left pawl 73 on the parking pawl 7 will be tightly pressed against the recess 42 of the parking cam 4, and the right pawl 72 will disengage from the parking ratchet 8. The parking motor 1 stops driving, and the parking ratchet 8 can rotate freely again, completing the disengagement process. Figure 2 The state shown.

[0034] Through the above-mentioned special scientific design, it has the following technical advantages: Firstly, the parking mechanism of this invention has a simple and compact structure, occupies little space, and is easy to operate and maintain. Excellent parking performance can be achieved by utilizing the cooperating parking motor 1, lead screw shaft 2, lead screw nut 3, parking cam 4, elastic element 5, pawl shaft 6, parking pawl 7, and parking ratchet 8.

[0035] Secondly, the parking mechanism of the present invention, through a special structural design, uses an elastic element 5 to replace the pre-tension spring and return spring in the prior art, which reduces the number of parts and greatly improves the reliability of the parking mechanism, and also significantly reduces manufacturing and maintenance costs.

[0036] Third, the parking mechanism of the present invention adopts a reduction mechanism in which the lead screw shaft 2 and the lead screw nut 3 cooperate, replacing the traditional gear rack, worm gear and other mechanisms. In particular, as described below, when the lead screw shaft 2 adopts a trapezoidal lead screw with a one-way self-locking function, the cost is lower, the mechanism size is smaller, and it is easier to arrange.

[0037] In this embodiment, a rotatable rolling element 74 is provided at the top pawl portion 73. The rolling element 74 contacts the parking cam 4 to buffer the thrust of the parking cam 4 on the parking pawl 7 and reduce wear on the parking pawl 7. This special structural design effectively solves the problems of easy wear of the parking ratchet, large parking force, and difficulty in parking in the later stage that exist in the prior art.

[0038] In this embodiment, the rolling element 74 is a cylindrical roller. This results in better rolling performance and further reduction of friction.

[0039] In this embodiment, the protrusion 41 of the parking cam 4 includes a cylindrical body, and the recess 42 includes a conical body connected to the protrusion 41. During subsequent reciprocating motions, regardless of whether the parking cam 4 rotates, the protrusion 41 of the cylindrical body and the recess 42 of the conical body ensure that each circumferential surface can effectively engage with the pawl 73. Whether lifting or accommodating, this prevents any movement jamming of the parking pawl 7, thus guaranteeing a smooth parking operation. The recess 42 of the conical body also facilitates sliding engagement with the pawl 73, resulting in better driving performance.

[0040] In this embodiment, a first cylindrical portion 43 is provided above the recessed portion 42 for abutting against the upper lead screw nut 3. The diameter of the first cylindrical portion 43 is smaller than the diameter of the protrusion 41 to avoid obstructing the movement of the top claw portion 73. The design of the first cylindrical portion 43 ensures the contact and engagement between the parking cam 4 and the upper lead screw nut 3, while preventing the lead screw nut 3 from obstructing the movement of the lower top claw portion 73. The top claw portion 73 can be well accommodated in the recessed portion 42 without causing any movement jamming to the parking pawl 7, thus ensuring a smooth parking operation.

[0041] In this embodiment, a second cylindrical portion 44 is provided below the protrusion 41. The second cylindrical portion 44 has a receiving space for the upper part of the elastic member 5 to extend into it to form a limiting protection for the elastic member 5. This can form a certain shell protection for the elastic member 5 and also form a limiting enclosure, ensuring that the elastic member 5 will not undergo unnecessary displacement and deformation, and ultimately ensuring a smooth parking operation.

[0042] In this embodiment, the force-applying part 71 is fork-shaped to allow the lead screw shaft 2 to move through the force-applying part 71. The parking pawl 7 also has a hollow part 75 between its upper and lower ends to reduce weight. The fork-shaped force-applying part 71 facilitates the movement of the lead screw shaft 2, making it easy to install in the early stage and replace and maintain later.

[0043] In this embodiment, the lead screw shaft 2 is a trapezoidal lead screw. When the trapezoidal lead screw has a one-way self-locking function, the lead screw nut 3 will not be displaced when locked, resulting in high driving accuracy, lower cost, smaller mechanism size, and easier arrangement.

[0044] In this embodiment, a guide ramp is provided on the contact surface between the pawl portion 72 and the parking ratchet 8 to facilitate engagement or disengagement between the pawl portion 72 and the parking ratchet 8. As shown in the figure, the guide ramp is... Figure 1 As shown at point G. This makes the pawl portion 72 on the right side of the parking pawl 7 more smooth and silky when engaging or disengaging with the parking ratchet 9, ultimately ensuring a smooth parking operation.

[0045] In this embodiment, one end of the drive shaft of the parking motor 1 is connected to the lead screw nut 3, and the other end of the drive shaft of the parking motor 1 protrudes from the top cover of the parking motor 1 to facilitate manual parking by manually turning the drive shaft. In this embodiment, the other end of the drive shaft of the parking motor 1 is provided with a recessed hexagonal socket head cap screw hole, such as... Figure 5 At point M shown, the drive shaft of the parking motor 1 can be turned using the matching external tools. This design effectively solves the technical problem of existing electronic parking mechanisms lacking a manual unlocking function. If a parking problem occurs, it can be manually unlocked, making it safer and more convenient.

[0046] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A parking mechanism, characterized in that: The system includes a parking motor (1), a lead screw shaft (2), a lead screw nut (3), a parking cam (4), an elastic element (5), a pawl shaft (6), a parking pawl (7), and a parking ratchet (8). The parking motor (1) and the lead screw shaft (2) are connected to drive the lead screw shaft (2) to rotate in both directions. The lead screw shaft (2) is fitted with the lead screw nut (3), the parking cam (4), and the elastic element (5) in sequence. The parking pawl (7) is rotatably mounted between the lead screw shaft (2) and the parking ratchet (8) via the pawl shaft (6). The lower end of the parking pawl (7) has a force-applying part (71) extending toward the lead screw shaft (2) to make the elastic element (5) rotate. The parking pawl (7) is pressed between the parking cam (4) and the force application part (71). The upper end of the parking pawl (7) is provided with a pawl part (72) extending toward the parking ratchet (8), and the other side of the upper end away from the pawl part (72) is provided with a top pawl part (73) that contacts the parking cam (4). The parking cam (4) is provided with a protrusion (41) and a recess (42). The protrusion (41) is used to press against the top pawl part (73) during parking operation so that the pawl part (72) and the parking ratchet (8) are engaged. The recess (42) is used to accommodate the top pawl part (73) during non-parking operation so that the pawl part (72) and the parking ratchet (8) are disengaged.

2. The parking mechanism according to claim 1, characterized in that: The top claw portion (73) is provided with a rotatable rolling element (74), which contacts the parking cam (4) to buffer the thrust of the parking cam (4) on the parking pawl (7) and reduce wear on the parking pawl (7).

3. The parking mechanism according to claim 2, characterized in that: The rolling element (74) is a cylindrical roller.

4. The parking mechanism according to claim 1, characterized in that: The protrusion (41) of the parking cam (4) includes a cylindrical body, and the recess (42) includes a conical body connected to the protrusion (41).

5. The parking mechanism according to claim 4, characterized in that: Above the recess (42) is a first cylindrical part (43) for abutting against the upper lead screw nut (3). The diameter of the first cylindrical part (43) is smaller than the diameter of the protrusion (41) so as not to hinder the movement of the top claw part (73).

6. The parking mechanism according to claim 4, characterized in that: Below the protrusion (41), there is a second cylindrical part (44), and the second cylindrical part (44) has a receiving space for the upper part of the elastic member (5) to extend into it to form a limiting protection for the elastic member (5).

7. The parking mechanism according to claim 1, characterized in that: The force-applying part (71) is fork-shaped to allow the lead screw shaft (2) to move through the force-applying part (71). The parking pawl (7) also has a hollow part (75) between its upper and lower ends for weight reduction.

8. The parking mechanism according to claim 1, characterized in that: The lead screw shaft (2) is a trapezoidal lead screw.

9. The parking mechanism according to claim 1, characterized in that: The pawl (72) is provided with a guide ramp at the contact surface with the parking ratchet (8) so as to facilitate the engagement or disengagement of the pawl (72) and the parking ratchet (8).

10. The parking mechanism according to claim 1, characterized in that: One end of the drive shaft of the parking motor (1) is connected to the lead screw nut (3), and the other end of the drive shaft of the parking motor (1) protrudes from the top cover of the parking motor (1) so that the manual parking operation can be performed by manually turning the drive shaft.

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