Auxiliary box gear shifting device with neutral gear

Abstract

The utility model provides an auxiliary box gear shifting device with a neutral gear. The auxiliary box gear shifting device with the neutral gear comprises a shell and an air cylinder which are arranged adjacently. A shifting fork shaft is axially arranged in a cavity of the shell and extends into the air cylinder from the cavity of the shell, a piston is arranged at the first end, located in the air cylinder, of the shifting fork shaft, a nut is arranged on the outer side of the piston, and the piston can axially move in the air cylinder. A groove is formed in the shifting fork shaft in the cavity, a steel ball, a self-locking spring and a screw plug are sequentially arranged at the position, corresponding to the groove, of the shell, and a straight line formed by the steel ball, the self-locking spring and the screw plug is perpendicular to the shifting fork shaft; a first air chamber is formed between the piston and the shell, the piston and the air cylinder form a second air chamber, a first spring is arranged in the first air chamber in the axial direction of the shifting fork shaft, and a second spring is arranged in the second air chamber in the axial direction of the shifting fork shaft. According to the auxiliary box gear shifting device with the neutral gear, the occupied space is reduced by arranging the single piston and the spring, and the auxiliary box gear shifting device is more suitable for being installed in a gearbox with the limited space.

Description

Technical Field

[0001] The present application belongs to the technical field of automobile transmissions, and in particular relates to an auxiliary box shifting device with a neutral gear. Background Art

[0002] The gearbox is a mechanism used to change the speed and torque from the engine, capable of varying the transmission ratio between the output and input shafts in fixed or step-by-step manner. The gearbox utilizes a main and auxiliary case design, with the auxiliary case utilizing an electronically controlled pneumatic shifting mechanism. Gear changes are achieved by axially moving the piston through cylinder ventilation. With the development of new energy electrification, the transmission requires a neutral position to ensure that the motor can adjust its speed without load during shifting. This position matches the speed ratio required by the target gear and avoids power interruption or shock during shifting.

[0003] Prior art employs a dual-piston design within the transmission's auxiliary cylinder structure to increase the neutral position. Specifically, the positions of the two pistons can be adjusted independently by controlling the air pressure at different air pressure control ports. When neutral is desired, the air pressure is adjusted to position the two pistons in a specific combination, bringing the overall cylinder into neutral.

[0004] However, the device for achieving neutral gear by providing a double piston has a complex structure, and because the auxiliary box of the transmission needs to accommodate two pistons, it usually takes up more space and is not suitable for installation in a transmission with limited space. Utility Model Content

[0005] The present application provides a sub-box shifting device with neutral gear, which is used to solve the problem that when achieving neutral gear by setting up double pistons, the device occupies too much space in the sub-box of the transmission due to its complex structure and is not suitable for installation in a transmission with limited space.

[0006] An embodiment of the present application provides a secondary box shifting device with a neutral gear, comprising: a housing and a cylinder arranged adjacent to each other;

[0007] A shift fork shaft is axially arranged in the cavity of the housing, and the shift fork shaft extends from the cavity of the housing into the cylinder. A piston is arranged on the first end of the shift fork shaft located in the cylinder, and a nut is arranged on the outer side of the piston. The piston can move axially inside the cylinder;

[0008] A groove is provided on the shift fork shaft in the cavity, and a steel ball, a self-locking spring and a screw plug are sequentially provided at positions corresponding to the groove on the housing. A straight line formed by the steel ball, the self-locking spring and the screw plug is perpendicular to the shift fork shaft, and the steel ball is closest to the shift fork shaft.

[0009] A first air chamber is formed between the piston and the housing, and a second air chamber is formed between the piston and the cylinder. A first spring is arranged in the first air chamber along the axial direction of the fork shaft, and a second spring is arranged in the second air chamber along the axial direction of the fork shaft.

[0010] In a possible implementation manner, the first spring is loosely mounted on the shift fork shaft in the first air chamber, and the second spring is loosely mounted on the nut.

[0011] In a possible implementation manner, the screw plug and the housing are connected via threads, and sealant is applied to the threads.

[0012] In a possible implementation manner, the nut is connected to the fork shaft via a thread.

[0013] In a possible implementation manner, the housing and the cylinder are fixedly connected by bolts.

[0014] In one possible embodiment, the device has three gears, namely low gear, neutral gear and high gear;

[0015] When the device is in a neutral state, neither the first air chamber nor the second air chamber is filled with air, the first spring and the second spring push the piston toward the middle area of the cylinder, and the steel ball enters the groove;

[0016] When the device is in a low gear state, air is introduced into the second air chamber of the piston, the piston overcomes the elastic force of the first spring and moves leftward, the steel ball overcomes the elastic force of the self-locking spring and exits the groove, and the piston is at the leftmost position of the cylinder;

[0017] When the device is in a high gear, air is introduced into the first air chamber of the piston, the piston overcomes the elastic force of the second spring and moves rightward, the steel ball overcomes the elastic force of the self-locking spring and exits the groove, and the piston is at the rightmost position of the cylinder.

[0018] In a possible implementation, in any gear state, the first spring (7), the second spring, and the self-locking spring are all in a compressed state.

[0019] In a possible implementation manner, the first spring and the second spring have the same shape and elastic parameters.

[0020] In a possible implementation manner, sealing rings are provided between the fork shaft and the piston, between the cylinder and the piston, and between the fork shaft and the housing, and a sealing gasket is provided between the housing and the cylinder.

[0021] In a possible implementation manner, the first sealing ring between the fork shaft and the housing is designed as a double-lip.

[0022] The present application provides a secondary case shift device with a neutral position, which retains the single piston arrangement found in conventional secondary case devices and utilizes three springs to achieve the neutral position of the secondary case device. Specifically, a first spring and a second spring are provided on the shift fork shaft on either side of the piston, respectively. The piston is secured in a neutral position by the elastic forces of the first and second springs. Furthermore, the self-locking spring cooperates with a steel ball to retain the steel ball in a groove when the device is in neutral, further ensuring the stability of the neutral position. Compared to a dual-piston design, the provision of a single piston and spring reduces space usage, making it more suitable for installation in space-constrained gearboxes. Furthermore, the provision of a single piston and three springs results in a lower manufacturing cost than a dual-piston design, thereby enhancing the market competitiveness of a secondary case shift device with a neutral position. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] Figure 1 This is a schematic diagram of the neutral state structure of the auxiliary box shift device with neutral gear;

[0025] Figure 2 This is a schematic diagram of the structure of the auxiliary box shift device in low gear state with neutral gear;

[0026] Figure 3 This is a schematic diagram of the high-gear structure of the auxiliary box shift device with neutral gear.

[0027] Reference numerals:

[0028] 1-fork shaft; 2-first sealing ring; 3-housing, 4-steel ball; 5-self-locking spring; 6-screw plug; 7-first spring; 8-second sealing ring; 9-sealing gasket; 10-piston; 11-third sealing ring; 12-nut; 13-second spring; 14-cylinder.

[0029] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the preferred embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] It should be noted that in the description of the embodiments of the present application, terms such as "upper", "lower", "inside", and "outside" indicating orientation or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description, and do not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present application.

[0032] In addition, it should be noted that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0033] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," and "fixed" should be interpreted broadly. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0034] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete way. In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete way.

[0035] In the prior art, since the device for achieving neutral gear by setting up dual pistons is complex in structure and occupies a large space, the dual piston gearbox auxiliary box is not suitable for gearboxes with limited space such as small cars.

[0036] The present application provides a secondary case shift device with a neutral position, which retains the single piston arrangement found in conventional secondary case devices and utilizes three springs to achieve the neutral position of the secondary case device. Specifically, a first spring and a second spring are provided on the shift fork shaft on either side of the piston, respectively. The piston is secured in a neutral position by the elastic forces of the first and second springs. Furthermore, the self-locking spring cooperates with a steel ball to retain the steel ball in a groove when the device is in neutral, further ensuring the stability of the neutral position. Compared to a dual-piston design, the provision of a single piston and spring reduces space usage, making it more suitable for installation in space-constrained gearboxes. Furthermore, the provision of a single piston and three springs results in a lower manufacturing cost than a dual-piston design, thereby enhancing the market competitiveness of a secondary case shift device with a neutral position.

[0037] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0038] Figure 1 A schematic diagram of the neutral state structure of a secondary box shift device with neutral gear provided in an embodiment of the present application; Figure 2 A schematic diagram of the low-gear structure of a secondary box shifting device with neutral gear provided in an embodiment of the present application; Figure 3 This is a schematic diagram of the high gear state structure of a secondary box shift device with neutral gear provided in an embodiment of the present application.

[0039] On the one hand, see Figures 1 to 3The present application provides a secondary gear shifting device with neutral gear, comprising: a housing (3) and a cylinder (14) arranged adjacent to each other. A shift fork shaft (1) is axially arranged in the cavity of the housing (3), and the shift fork shaft (1) extends from the cavity of the housing (3) into the cylinder (14). A piston (10) is arranged on the first end of the shift fork shaft (1) located in the cylinder (14), and a nut 12 is arranged on the outside of the piston (10). The piston (10) can move axially inside the cylinder (14); a groove is arranged on the shift fork shaft (1) in the cavity, and steel balls (4) are arranged in sequence at positions corresponding to the groove on the housing (3). , a self-locking spring (5) and a screw plug (6); a straight line formed by the steel ball (4), the self-locking spring (5) and the screw plug (6) is perpendicular to the shift fork shaft (1); the steel ball (4) is closest to the shift fork shaft (1); a first air chamber is formed between the piston (10) and the housing (3); the piston (10) and the cylinder (14) form a second air chamber; a first spring (7) is arranged in the first air chamber along the axial direction of the shift fork shaft (1); and a second spring (13) is arranged in the second air chamber along the axial direction of the shift fork shaft (1).

[0040] In the present application, a sub-box shifting device with neutral gear is mainly composed of a housing (3) and a cylinder (14) arranged adjacent to each other, wherein the housing (3) and the cylinder (14) are fixedly connected by bolts, and the bolted connection is achieved by passing the bolts through the reserved holes on the housing (3) and the cylinder (14) and tightening the nuts (12) to achieve the fastening between the two to ensure the stability between the housing (3) and the cylinder (14). The shift fork shaft (1) is axially arranged in the cavity of the housing (3) and extends from the cavity of the housing (3) to the cylinder (14). The shift fork shaft (1) is a key component of the shifting device, and its movement will drive the shifting mechanism connected to the shift fork shaft 1 to perform a shifting operation. The piston (10) is arranged on the shift fork shaft (1) and is located on the first end of the cylinder (14), with reference to Figure 1 The piston (10) is arranged on the fork shaft (1) and is located at the right end of the cylinder (14). The nut (12) is connected to the outer side of the piston (10) through a thread. The nut (12) fixes the piston (10) so that it does not deviate and also transmits the thrust or pull of the air pressure in the cylinder (14) to the piston through the threaded connection. When the air pressure on both sides of the piston (10) in the cylinder (14) changes, the piston (10) will be subjected to the corresponding thrust or pull, and then move axially inside the cylinder (14).

[0041] Further, refer to Figure 1A steel ball (4), a self-locking spring (5), and a screw plug (6) are sequentially arranged from bottom to top on a housing (3) corresponding to the groove, i.e., the distance between the steel ball (4) and the shift fork shaft (1) is the shortest, and a straight line formed by the steel ball (4), the self-locking spring (5), and the screw plug (6) is perpendicular to a straight line formed by the shift fork shaft (1). The groove is arranged on the shift fork shaft (1) and is located in the cavity of the housing (3), providing a space for the steel ball (4) to be embedded. When the shift fork shaft (1) is in a neutral position, the steel ball (4) is embedded in the groove, thereby locking the shift fork shaft (1) and preventing the shift fork shaft (1) from moving accidentally. The steel ball (4) is held in a position where it can contact the groove of the shift fork shaft (1) by the elastic force of the self-locking spring (5) when the auxiliary box shift device with neutral gear is in the neutral position, and under the elastic force of the self-locking spring (5), the steel ball (4) can be embedded in the groove of the shift fork shaft (1), realizing the locking function of the auxiliary box shift device with neutral gear, and when shifting gears is required, the steel ball (4) overcomes the elastic force of the self-locking spring (5) and exits the groove, allowing the shift fork shaft (1) to move. The self-locking spring (5) is located between the steel ball (4) and the screw plug (6), providing sufficient elastic force for the steel ball (4) so that the steel ball (4) can be held in a position where it can be embedded in the groove of the shift fork shaft (1). The screw plug (6) is arranged on the housing (3) and connected to the housing (3) by a thread. Optionally, the sealing is ensured by applying a sealant.

[0042] Furthermore, the piston (10) is placed in the cylinder (14), and the cylinder (14) is arranged adjacent to the housing (3). A first air chamber is formed between the piston (10) and the housing (3). The outer side of the piston (10) and the inner wall of the cylinder (14) form a second air chamber. The first air chamber and the second air chamber respectively affect the position of the piston (10) by controlling the intake of air, thereby achieving gear shifting. In the first air chamber, a first spring (7) is arranged along the axial direction of the shift fork shaft (1). When the first air chamber is not filled with air, the first spring (7) pushes the piston (10) to the middle area of the cylinder (14) to form a neutral gear, or in the low gear state, prevents the piston 10 from moving to the left due to excessive intake of air in the second air chamber. A second spring (13) is provided in the second air chamber along the axial direction of the nut (12) to push the piston (10) toward the middle position of the cylinder (14) when no air is introduced into the second air chamber, or to prevent the piston (10) from excessively moving to the right due to air introduction into the first air chamber in a high-speed state.

[0043] See also Figure 1 In the embodiment of the present application, the first spring (7) is loosely mounted on the fork shaft (1) in the first air chamber, and the second spring (13) is loosely mounted on the nut (12).

[0044] In the present application, the first spring (7) is mounted on the shift fork shaft (1) in the first air chamber in an empty sleeve manner, and does not directly generate friction with the shift fork shaft (1) or hinder the rotation of the shift fork shaft 1, thereby allowing the shift fork shaft (1) to rotate smoothly during the shifting process, and at the same time, the first spring (7) can provide the necessary elastic force along the axial direction of the shift fork shaft (1). Similarly, the second spring (13) is also mounted on the nut (12) in an empty sleeve manner, rather than being directly mounted on the shift fork shaft (1).

[0045] The nut (12) is connected to the fork shaft (1) by a threaded connection. The nut (12) can fix the piston (10) and transmit thrust. The second spring (13) is loosely sleeved on the nut (12). Therefore, the nut (12) and the fork shaft (1) together constitute the support structure of the second spring (13). The second spring (13) uses the structure of the nut (12) to maintain its position and provide elastic force.

[0046] See also Figure 1 In the embodiment of the present application, the screw plug (6) and the housing (3) are connected by threads, and sealant is applied to the threads.

[0047] In the present application, the screw plug (6) and the housing (3) are connected by threads, and a sealant is applied to the threads to enhance the sealing performance of the connection. The sealant can fill the tiny gaps in the threaded joint and effectively prevent the penetration of liquids, gases or impurities, thereby improving the sealing performance of the threaded connection and preventing leakage and loosening.

[0048] See also Figure 1 , Figure 2 and Figure 3 In the embodiment of the present application, the device has three gears, namely low gear, neutral gear and high gear; when the device is in the neutral gear state, neither the first air chamber nor the second air chamber is fed with air, the first spring (7) and the second spring (13) push the piston (10) to the middle area of the cylinder (14), and the steel ball (4) enters the groove; when the device is in the low gear state, the second air chamber of the piston (10) is fed with air, the piston (10) overcomes the elastic force of the first spring (7) and moves to the left, the steel ball (4) overcomes the elastic force of the self-locking spring (5) and exits the groove, and the piston (10) is at the leftmost position of the cylinder (14); when the device is in the high gear state, the first air chamber of the piston (10) is fed with air, the piston (10) overcomes the elastic force of the second spring (13) and moves to the right, the steel ball (4) overcomes the elastic force of the self-locking spring (5) and exits the groove, and the piston (10) is at the rightmost position of the cylinder (14).

[0049] In this application, Figure 1 This is a neutral state structure diagram of a secondary gear shift device with neutral gear, such as Figure 1As shown, when the device is in the neutral position, neither the first air chamber nor the second air chamber is filled with air. When the first air chamber is not filled with air, the elastic force of the first spring (7) is the main force for pushing the piston (10), and the first spring (7) can push the piston (10) to the middle area of the cylinder (14). This thrust ensures the stable position of the piston (10) in the neutral state. When the second air chamber is not filled with air, the elastic force of the second spring (13) is also the main force for pushing the piston (10). The first spring (7) and the second spring (13) work together to push the piston (10) to the middle area of the cylinder (14). When the device is in a neutral state, the steel ball (4) enters the groove of the fork shaft (1) under the elastic force of the self-locking spring (5), and the shape and size of the groove match the steel ball (4) to ensure that the steel ball (4) can smoothly enter and remain in the groove. The locking mechanism of the self-locking spring (5) effectively prevents the piston (10) from moving in an uncontrolled manner, thereby ensuring the stability and safety of the device in the neutral state.

[0050] Figure 2 This is a low gear state structure diagram of a sub-box shift device with neutral gear, such as Figure 2 As shown, when the device is in the low gear state, the right side of the piston (10), that is, the second air chamber, is filled with air. As the second air chamber is filled with air, the gas pressure gradually increases, generating a leftward thrust on the piston (10). During the process of the piston (10) moving leftward, the piston (10) overcomes the elastic force of the first spring (7) and moves leftward. Since the piston (10) moves leftward, the shift fork shaft (1) also moves leftward. Therefore, the steel ball (4) originally in the state of being in the neutral gear is now out of the groove by overcoming the elastic force of the self-locking spring (5). Finally, when the piston (10) is at the leftmost position of the cylinder (14), the auxiliary box shift device with neutral gear is in the low gear state.

[0051] Figure 3 This is a high-gear state structure diagram of a secondary gear shift device with neutral gear, such as Figure 3 As shown, when the device is in the high-speed state, the left side of the piston (10), that is, the first air chamber, is filled with air. As the first air chamber is filled with air, the gas pressure gradually increases, generating a rightward thrust on the piston (10), so that the piston (10) overcomes the elastic force of the second spring (13) and moves to the right. As the piston (10) moves to the right, the piston (10) drives the shift fork shaft (1) to move to the right. Therefore, the steel ball (4) originally in the state of being in the neutral gear in the groove, due to the rightward movement of the shift fork shaft (1), the steel ball (4) overcomes the elastic force of the self-locking spring (5) and exits the groove. Finally, when the piston (10) is in the most secure position of the cylinder (14), the auxiliary box shift device with neutral gear is in the high-speed state.

[0052] In any gear state, the first spring (7), the second spring (13), and the self-locking spring (5) are all in a compressed state. In addition, the first spring (7) and the second spring (13) have the same shape and elastic parameters, that is, when the first spring (7) and the second spring (13) have the same compression amount, the first spring (7) and the second spring (13) generate the same elastic force, that is, when the device is in a neutral state, it can ensure that the piston (10) is in the middle position of the cylinder (14).

[0053] See also Figure 1 In the embodiment of the present application, sealing rings are provided between the fork shaft (1) and the piston (10), between the cylinder (14) and the piston, and between the fork shaft (1) and the housing (3), and a sealing gasket is provided between the housing (3) and the cylinder (14).

[0054] In the present application, a second sealing ring (8) is provided between the fork shaft (1) and the piston (10) to ensure that there is no gap between the fork shaft (1) and the piston (10), so as to prevent the gas in the first air chamber and the second air chamber from leaking through the gap between the fork shaft (1) and the piston (10). A third sealing ring (11) is provided between the cylinder (14) and the piston (10) to prevent the gas in the cylinder (14) from leaking to the outside, and also to prevent external impurities from entering the cylinder (14) through the gap between the cylinder (14) and the piston (10). A first sealing ring (2) is provided between the fork shaft (1) and the housing (3) to ensure that dust or water vapor outside the housing (3) cannot enter the interior of the device, thereby ensuring that the interior of the device is clean and dry. A sealing gasket (9) is provided between the housing (3) and the cylinder (14) to ensure that the connection between the housing (3) and the cylinder (14) has good sealing performance. In summary, sealing rings and sealing gaskets are provided between the fork shaft (1) and the piston (10), between the cylinder (14) and the piston (10), between the fork shaft (1) and the housing (3), and between the housing (3) and the cylinder (14) to ensure the sealing between the various components inside the device, prevent gas leakage inside the device and the intrusion of external impurities, thereby ensuring the normal operation and performance stability of the device.

[0055] See also Figure 1 In the embodiment of the present application, the first sealing ring (2) between the fork shaft (1) and the housing (3) is a double-lip design.

[0056] In the present application, a double-lip seal ring is composed of two relatively independent sealing lips, which are respectively referred to as an inner lip and an outer lip. The inner lip is usually in close contact with the fork shaft (1), forming a first sealing barrier; while the outer lip is in contact with the housing (3), forming a second sealing barrier. This double sealing structure greatly improves the sealing effect, making it possible to effectively prevent the leakage of lubricating oil or working medium even in harsh working environments.

[0057] In summary, the present application provides a sub-box shifting device with neutral gear, comprising: a housing (3) and a cylinder (14) arranged adjacent to each other; and through the design of a single piston (10) and a cylinder (14), in conjunction with the groove on the shift fork shaft (1), a steel ball (4) and a self-locking spring (5), the switching of three gears, namely low gear, neutral gear and high gear, is achieved, which greatly reduces the space occupied. Compared with the double-piston design, the present application provides a sub-box shifting device with neutral gear, which is more suitable for a transmission sub-box with limited space. When neither the first air chamber nor the second air chamber is filled with air, the first spring (7) and the second spring (13) work together to push the piston (10) toward the middle area of the cylinder (14). At this time, the steel ball (4) enters the groove on the shift fork shaft (1) under the elastic force of the self-locking spring (5), achieving self-locking, and the device is in a neutral gear state. The design of the self-locking spring (5) cleverly utilizes the cooperation between the spring and the steel ball to achieve automatic locking of the neutral gear. By inflating the first air chamber or the second air chamber, the elastic force of the corresponding spring can be overcome, pushing the piston (10) to move to the left or right. At the same time, the steel ball (4) will overcome the elastic force of the self-locking spring (5) and exit the groove, allowing the piston (10) to continue to move to the leftmost or rightmost position, thereby achieving low gear or high gear switching. Due to the use of a single piston design, compared with a double piston design, space is greatly saved. This makes the device easier to install and use in a gearbox with limited space. In addition, by arranging a second sealing ring (8) between the fork shaft (1) and the piston (10), a third sealing ring (11) between the cylinder (14) and the piston (10), a first sealing ring (2) between the fork shaft (1) and the housing (3), and a sealing gasket (9) between the housing (3) and the cylinder (14), the airtightness of the device is ensured, and the influence of gas leakage on the shifting performance is prevented.

[0058] The serial numbers of the embodiments of this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are only preferred embodiments of this application and do not limit the scope of the patent of this application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of this application.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A sub-box shifting device with neutral gear, characterized in that: include: A housing (3) and a cylinder (14) are arranged adjacent to each other; A shift fork shaft (1) is axially arranged in the cavity of the housing (3), and the shift fork shaft (1) extends from the cavity of the housing (3) into the cylinder (14). A piston (10) is arranged on the first end of the shift fork shaft (1) located in the cylinder (14), and a nut (12) is arranged on the outside of the piston (10). The piston (10) can move axially inside the cylinder (14); A groove is provided on the shift fork shaft (1) in the cavity, and a steel ball (4), a self-locking spring (5) and a screw plug (6) are sequentially provided at positions corresponding to the groove on the housing (3), wherein a straight line formed by the steel ball (4), the self-locking spring (5) and the screw plug (6) is perpendicular to the shift fork shaft (1), and the steel ball (4) is closest to the shift fork shaft (1); A first air chamber is formed between the piston (10) and the housing (3), and a second air chamber is formed between the piston (10) and the cylinder (14). A first spring (7) is arranged in the first air chamber along the axial direction of the shift fork shaft (1), and a second spring (13) is arranged in the second air chamber along the axial direction of the shift fork shaft (1).

2. The device according to claim 1, characterized in that The first spring (7) is loosely sleeved on the shift fork shaft (1) in the first air chamber, and the second spring (13) is loosely sleeved on the nut (12).

3. The device according to claim 1, characterized in that The screw plug (6) and the housing (3) are connected via threads, and the threads are coated with sealant.

4. The device according to claim 1, characterized in that The nut (12) is connected to the fork shaft (1) via threads.

5. The device according to any one of claims 1 to 4, characterized in that The housing (3) and the cylinder (14) are fixedly connected via bolts.

6. The device according to any one of claims 1 to 4, characterized in that The device has three gears, namely low gear, neutral gear and high gear; When the device is in a neutral state, neither the first air chamber nor the second air chamber is filled with air, the first spring (7) and the second spring (13) push the piston (10) toward the middle area of the cylinder (14), and the steel ball (4) enters the groove; When the device is in a low gear state, air is introduced into the second air chamber of the piston (10), the piston (10) overcomes the elastic force of the first spring (7) and moves to the left, the steel ball (4) overcomes the elastic force of the self-locking spring and exits the groove, and the piston (10) is at the leftmost position of the cylinder (14); When the device is in a high gear, air is introduced into the first air chamber of the piston (10), the piston (10) overcomes the elastic force of the second spring (13) and moves to the right, the steel ball (4) overcomes the elastic force of the self-locking spring and exits the groove, and the piston (10) is at the rightmost position of the cylinder (14).

7. The device according to claim 6, characterized in that In any gear state, the first spring (7), the second spring (13), and the self-locking spring (5) are all in a compressed state.

8. The device according to any one of claims 1 to 4, characterized in that The first spring (7) and the second spring (13) have the same shape and elastic parameters.

9. The device according to any one of claims 1 to 4, characterized in that Sealing rings are provided between the shift fork shaft (1) and the piston (10), between the cylinder (14) and the piston, and between the shift fork shaft (1) and the housing (3), and a sealing gasket is provided between the housing (3) and the cylinder (14).

10. The device according to claim 7, characterized in that The first sealing ring (2) between the shift fork shaft (1) and the housing (3) is designed with double lips.

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