Pneumatic control operating mechanism capable of locking 1 / reverse gear

Abstract

The invention provides a pneumatic control operating mechanism capable of locking a first / reverse gear, which belongs to the technical field of gearboxes and comprises a small cover, a gear shifting shaft assembly, a fan-shaped self-locking block, a driving pin, a gear shifting block, a gear selecting rotating arm, a gear selecting shaft, a stop valve, a connecting air pipe, a two-position five-way valve, a high-gear air pipe assembly, a low-gear air pipe and a locking air cylinder. The first-gear large-speed-ratio 12.6 gearbox requirement of the crane market can be met, when the gearbox is engaged with the high gear, locking needs to be completed at the first / reverse gear selecting position, the first / reverse gear selecting action is not carried out, gear selecting and shifting are convenient, and the locking structure is simple.

Description

Technical Field

[0001] The invention belongs to the technical field of gearboxes, and specifically discloses a gas-controlled operating mechanism capable of locking a 1st gear position and a reverse gear position. Background Art

[0002] In order to meet the demand for a gearbox with a large head gear ratio of 12.6 in the 25t crane market and to meet the requirement for uniform speed ratio step difference, it is necessary to retain only the low gear for the 1 / reverse gear position where the head gear ratio is located. In high gear, the 1 / reverse high gear ratio is not required. Therefore, in this case, when the gearbox is in high gear, 1 / reverse gear cannot be selected when selecting gears. The 1 / reverse gear position in high gear needs to be locked to avoid mis-engagement. At this time, it is necessary to design an operating mechanism that can lock the 1 / reverse gear in high gear, and the mechanism is required to be easy to select and shift and have a simple locking structure. Summary of the invention

[0003] In order to meet the demand for a gearbox with a large speed ratio of 12.6 in the first gear in the crane market, when the gearbox is in a high gear, the 1 / reverse gear selection position must be locked and the 1 / reverse gear selection action is not performed. The present invention provides a pneumatic control mechanism that can lock the 1 / reverse gear position and has easy gear selection and shifting, a simple locking structure, and a simple locking structure.

[0004] The above-mentioned pneumatic control mechanism capable of locking the 1st / reverse gear position comprises a small cover, a shift shaft assembly, a fan-shaped self-locking block, a driving pin, a shift dial head, a gear selection arm, a shift shaft, a stop valve, a connecting air pipe, a two-position five-way valve, a high-speed air pipe assembly, a low-speed air pipe and a locking cylinder; the shift shaft assembly comprises a shift connecting shaft, a shift spline sleeve and a shift shaft; the shift connecting shaft passes through the small cover; the shift spline sleeve, the shift shaft, the fan-shaped self-locking block, the shift dial head and the gear selection arm are located inside the small cover; the right end of the shift connecting shaft is fixedly connected to the left end of the shift spline sleeve as a whole, and the shift connecting shaft and the shift spline sleeve can only rotate axially in the small cover, and cannot move axially; the left end of the shift shaft is connected to the right end of the shift spline sleeve by a spline, and the shift shaft can be Axial rotation and axial movement; the fan-shaped self-locking block is provided with an axial hole, an axial through groove is provided in the axial hole, and an M groove is provided on the surface of the fan-shaped self-locking block, and the M groove includes a middle groove and protrusions on both sides of the middle groove; the driving pin passes through the shift shaft vertically; the shift shaft and the driving pin pass through the axial hole of the fan-shaped self-locking block, and the end of the driving pin is located in the axial through groove of the fan-shaped self-locking block; the shift dial head fixing sleeve is arranged outside the shift shaft; the shift selector arm overlaps the shift dial head; the shift selector shaft passes through the small cover, and the end located in the small cover is fixedly connected to the shift selector arm; port 1 of the shut-off valve is connected to the air source of the whole vehicle, and port 2 of the shut-off valve is connected to port 1 of the two-position five-way valve through a connecting air pipe, and the top pin of the shut-off valve passes through the small cover and is located in the middle groove of the M groove of the fan-shaped self-locking block. The fan-shaped self-locking block rotates to control the telescopic control of the ejector pin 1 and 2 to connect and disconnect; the high-speed air pipe assembly includes high-speed air pipe Ⅰ, high-speed air pipe Ⅱ and high-speed air pipe Ⅲ that are interconnected; the 21st port of the two-position five-way valve is connected to the low-speed air inlet of the auxiliary box cylinder through the low-speed air pipe, and the 22nd port of the two-position five-way valve is connected to the high-speed air inlet of the auxiliary box cylinder through the high-speed air pipe Ⅰ and the high-speed air pipe Ⅱ. The 31st and 32nd ports of the two-position five-way valve are exhaust ports, and the 4th port of the two-position five-way valve is a control port. When there is no air source at the 4th port of the two-position five-way valve, the 1st port is connected to the 22nd port, and the 21st port is connected to the 31st port. When the 4th port of the two-position five-way valve is ventilated, the 1st port is connected to the 21st port, and the 22nd port is connected to the 32nd port; the locking cylinder includes a cylinder body, a locking piston and a spring. The cylinder body is connected to the right end of the small cover, and is provided with a first chamber and a second chamber. A piston hole is provided between the first chamber and the second chamber. The first chamber is connected to the 22nd port of the two-position five-way valve through the high-speed air pipe I and the high-speed air pipe III, and the second chamber is connected to the small cover; the locking piston includes a piston disc and a piston rod connected to the piston disc; the piston disc is located in the first chamber, and the elastic reset member and the gas provided by the 22nd port of the two-position five-way valve are located on both sides of the piston disc; when the piston rod is in low gear, it is located at the front side of the right end of the shift shaft through the elastic reset member, allowing the shift shaft to move right, and the 1 / reverse gear lock is released. When the piston rod is in high gear, it extends backward through the piston hole through the air pressure to prevent the shift shaft from moving right, and the 1 / reverse gear lock is released.

[0005] In the above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position, the connecting air pipe and the high-gear air pipe III are disc-shaped air pipes.

[0006] In the above-mentioned air-controlled operating mechanism capable of locking the 1st / reverse gear position, the small cover comprises a small cover end cover and a small cover shell; the left side of the small cover shell is fixedly connected to the small cover end cover, and the right side is fixedly connected to the cylinder body of the locking cylinder.

[0007] In the above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position, the right end of the gear shift connecting shaft is welded to the left end of the gear shift spline sleeve.

[0008] In the above-mentioned pneumatic control mechanism capable of locking the 1st / reverse gear position, the shift spline sleeve is axially limited in the small cover end cover by a cylindrical pin.

[0009] In the above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position, the shift knob and the shift shaft are elastically and fastened in connection via an elastic pin.

[0010] In the above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position, the elastic return member is a return spring.

[0011] The above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position also includes a pressure reducing valve; a pressure reducing valve is also installed between the stop valve and the air source of the whole vehicle.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The invention can meet the demand for a gearbox with a large speed ratio of 12.6 in the first gear in the crane market. When the gearbox is in a high gear, the 1 / reverse gear selection position must be locked without performing the 1 / reverse gear selection action. The gear selection and shifting is easy and the locking structure is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 The three-dimensional appearance diagram of the gas-controlled operating mechanism capable of locking the 1st / reverse gear position;

[0016] Figure 2 The internal structure diagram of the gas-controlled operating mechanism capable of locking the 1st / reverse gear position;

[0017] Figure 3 It is a schematic diagram of the connection between the shift knob and the shift shaft;

[0018] Figure 4 Schematic diagram of the connection between the fan-shaped self-locking block and the shift shaft (the direction of the arrow in the figure is the swing direction of the fan-shaped self-locking block and the shift shaft);

[0019] Figure 5 A schematic diagram of the high-barrier air pipe assembly.

[0020] In the figure: 1-small cover end cover; 2-small cover housing; 3-shift connecting shaft; 4-shift spline sleeve; 5-cylindrical pin; 6-shift shaft; 7-fan-shaped self-locking block; 7.1-M groove; 8-driving pin; 9-shift dial head; 10-elastic pin; 11-locking piston; 12-high-speed air pipe assembly; 12.1-high-speed air pipe I; 12.2-high-speed air pipe II; 12.3-high-speed air pipe III; 13-low-speed air pipe; 14-two-position five-way valve; 15-connecting air pipe; 16-stop valve; 17-shift arm; 18-pressure reducing valve; 19-shift shaft; 20-shift rocker arm; 21-reset spring. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0022] The terms "left", "right", "front", "back", etc. used in the patent application specification and claims of the present invention are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly. The accompanying drawings are only structural schematic diagrams and are not strictly drawn according to the actual scale. The specific size and quantity of each structure can be determined according to actual needs.

[0023] The present embodiment provides a pneumatically controlled operating mechanism capable of locking the 1st / reverse gear, comprising a small cover, a shift shaft assembly, a fan-shaped self-locking block 7, a drive pin 8, a shift dial head 9, a gear selection arm 17, a gear selection shaft 19, a stop valve 16, a connecting air pipe 15, a two-position five-way valve 14, a high-gear air pipe assembly 12, a low-gear air pipe 13, a locking cylinder and a pressure reducing valve 18.

[0024] The small cover is used to support the shift shaft assembly, and comprises a small cover end cover 1 and a small cover housing 2 , wherein the left side of the small cover housing 2 is fixedly connected to the small cover end cover 1 .

[0025] The shift shaft assembly includes a shift connecting shaft 3, a shift spline sleeve 4 and a shift shaft 6; the shift connecting shaft 3 passes through the small cover; the shift spline sleeve 4, the shift shaft 6, the fan-shaped self-locking block 7, the shift dial head 9, and the gear selection arm 17 are located in the small cover; the right end of the shift connecting shaft 3 and the left end of the shift spline sleeve 4 are fixedly connected to each other by welding, and the shift spline sleeve 4 is axially limited in the small cover end cover 1 by a cylindrical pin 5, and the shift connecting shaft 3 and the shift spline sleeve 4 can only rotate axially in the small cover, and cannot move axially; the left end of the shift shaft 6 is connected to the right end of the shift spline sleeve 4 by a spline, so that the shift shaft 6 can move axially between the shift spline sleeve 4 and the small cover housing 2, and at the same time, the spline engagement ensures that the shift shaft 6 can swing synchronously with the shift connecting shaft 3 when the shift rocker arm swings.

[0026] The fan-shaped self-locking block 7 is provided with an axial hole, in which an axial through groove is provided, and the surface of the fan-shaped self-locking block 7 is provided with an M groove 7.1, which includes a middle groove and protrusions located on both sides of the middle groove.

[0027] The drive pin 8 vertically passes through the shift shaft 6; the shift shaft 6 and the drive pin 8 pass through the axial hole of the fan-shaped self-locking block 7, and the end of the drive pin 8 is located in the axial through groove of the fan-shaped self-locking block 7.

[0028] The shift knob 9 is fixedly sleeved outside the shift shaft 6 , and the two are elastically fastened and connected via an elastic pin 10 .

[0029] The gear selection arm 17 overlaps the gear shift knob 9 .

[0030] The gear selection shaft 19 passes through the small cover, and the end located inside the small cover is fixedly connected to the gear selection rotating arm 17 , and the end located outside the small cover is fixedly connected to the gear selection rocker arm 20 .

[0031] The air inlet of the pressure reducing valve 18 is connected to the air source of the whole vehicle, the air outlet of the pressure reducing valve 18 is connected to the port 1 of the stop valve 16, the port 2 of the stop valve 16 is connected to the port 1 of the two-position five-way valve 14 through the connecting air pipe 15, the top pin of the stop valve 16 passes through the small cover and is located in the middle groove of the M groove 7.1 of the fan-shaped self-locking block 7, and the fan-shaped self-locking block 7 rotates to make the top pin telescopic to control the connection and disconnection of ports 1 and 2.

[0032] The high-barrier air pipe assembly 12 comprises a high-barrier air pipe I 12.1, a high-barrier air pipe II 12.2 and a high-barrier air pipe III 12.3 which are interconnected.

[0033] Port 21 of the two-position five-way valve 14 is connected to the low-speed air inlet of the auxiliary box cylinder through the low-speed air pipe 13, and port 22 of the two-position five-way valve 14 is connected to the high-speed air inlet of the auxiliary box cylinder through the high-speed air pipe Ⅰ12.1 and the high-speed air pipe Ⅱ12.2. Ports 31 and 32 of the two-position five-way valve 14 are exhaust ports, and port 4 of the two-position five-way valve 14 is a control port. When there is no air source at port 4 of the two-position five-way valve 14, port 1 is connected to port 22, and port 21 is connected to port 31. When port 4 of the two-position five-way valve is ventilated, port 1 is connected to port 21, and port 22 is connected to port 32.

[0034] The locking cylinder includes a cylinder body, a locking piston 11 and an elastic reset member; the cylinder body is connected to the right end of the small cover housing 2, and is provided with a first chamber and a second chamber, a piston hole is provided between the first chamber and the second chamber, the first chamber is connected to the 22nd port of the two-position five-way valve 14 through the high-speed air pipe I 12.1 and the high-speed air pipe III 12.3, and the second chamber is connected to the small cover housing 2; the locking piston 11 includes a piston disc and a piston rod connected to the piston disc; the piston disc is located in the first chamber, and the elastic reset member and the gas provided by the 22nd port of the two-position five-way valve 14 are located on both sides of the piston disc; the piston rod is located at the front side of the right end of the shift shaft 6 by the elastic reset member in low gear, allowing the shift shaft 6 to move right, and the 1 / reverse gear lock is released, and the piston rod is extended backward through the piston hole by the air pressure in high gear, preventing the shift shaft 6 from moving right, and the 1 / reverse gear lock is locked. The elastic reset member is a reset spring 21.

[0035] In the above-mentioned pneumatic control mechanism capable of locking the 1 / reverse gear, the shift spline sleeve 4 and the shift connecting shaft 3 are welded into one body, so that when the shift rocker arm is operated, the shift spline sleeve 4 and the shift connecting shaft 3 swing as a whole; the shift spline sleeve 4 and the shift shaft 6 are spline-connected, which realizes the circumferential limit of the shift shaft 6 and also ensures that the shift shaft 6 can move axially between the shift spline sleeve 4 and the small cover housing 2, so as to realize gear locking; the fan-shaped self-locking block 7 is installed on the shift shaft 6 through the driving pin 8, and the driving pin 8 is overlapped and connected with the fan-shaped self-locking block 7 through the axial through groove, and the driving pin 8 ensures that when the shift shaft 6 moves axially, the fan-shaped self-locking block 7 does not work, and the shift When the gear shaft 6 swings, the driving pin 8 drives the fan-shaped self-locking block 7 to swing synchronously, controlling the on and off of the stop valve 16; the shift dial head 9 is connected to the shift shaft 6 by the elastic pin 10, so that the shift shaft 6 and the shift dial head 9 can move synchronously, and the shift shaft 6 can move axially to select gears; the stop valve 16 and the two-position five-way valve 14 are used to realize the air circuit control of high and low gears, among which the stop valve 16 is the main switch to realize the on and off of the air circuit, and the two-position five-way valve 14 is the pre-selection switch to realize the on and off of the high and low gear air circuit; the connecting air pipe 15 and the high-gear air pipe III 12.3 are connected in a space with a small distance, and a disc-shaped air pipe is used to ensure the normal ventilation of the air circuit while realizing flexible and convenient installation in a small space.

[0036] The working process of the above-mentioned gas-controlled operating mechanism capable of locking the 1st / reverse gear position is as follows.

[0037] ① Shifting function of the shift shaft assembly: When selecting a gear, the top pin of the stop valve 16 is located in the middle groove of the M groove 7.1 of the fan-shaped self-locking block 7, the stop valve 16 is in the ventilation state, the fan-shaped self-locking block 7 is connected to the shift shaft 6 through the driving pin 8, but the driving pin 8 is installed in the axial through groove of the fan-shaped self-locking block 7 and can move axially. When the gear selection rocker arm 20 swings to drive the gear selection rotating arm 17 to rotate, the gear selection rotating arm 17 overlaps the head of the gear shifting head 9, and the gear selection rotating arm 17 drives the gear shifting head 9 to move axially along the direction of the gear shifting shaft 6, and the gear shifting head 9 and the gear shifting shaft 6 are elastically fastened by the elastic pin 10 The shifting head 9 and the shifting shaft 6 are connected to realize synchronous movement of the shifting head 9 and the shifting shaft 6, and the driving pin 8 moves axially in the axial through groove of the fan-shaped self-locking block 7, and finally realizes the axial movement of the shifting shaft 6 in the small cover to realize gear selection; when shifting gears, the shift rocker arm drives the shifting shaft assembly to swing circumferentially, and the shifting shaft 6 drives the shifting head 9 to swing back and forth to realize gear shifting. At this time, the shifting shaft 6 drives the driving pin 8 to swing, and the driving pin 8 acts on one side of the axial through groove of the fan-shaped self-locking block 7 to drive the fan-shaped self-locking block 7 to swing. The top pin of the stop valve 16 is located at the protrusion of the M groove 7.1, the top pin is compressed, and the air circuit of the stop valve 16 is disconnected.

[0038] ② The auxiliary box switching function of the stop valve 16: When the auxiliary box switches between high and low gears, the main box is required to be in neutral gear, that is, the top pin of the stop valve 16 is located in the middle groove of the M groove 7.1 of the fan-shaped self-locking block 7. At this time, port 1 and port 2 inside the stop valve 16 are connected, and the vehicle air source enters the auxiliary box cylinder through the high and low gear air pipes through the pressure reducing valve 18, the stop valve 16, and the two-position five-way valve 14 to realize the high and low gear switching of the auxiliary box; if the main box is not returned to neutral gear, when a certain gear is engaged, the top pin of the stop valve 16 is located at the protrusion of the M groove 7.1 of the fan-shaped self-locking block 7, the top pin is compressed, and port 1 and port 2 inside the stop valve 16 are blocked. The vehicle air source cannot pass through the pressure reducing valve 18 to the stop valve 16, and the auxiliary box cannot be engaged. The stop valve 16 becomes the air circuit switch for the high and low gear switching of the auxiliary box.

[0039] ③ High and low gear switching and gear selection locking air circuit: When the auxiliary box switches high and low gears, the main box is idle, and the air source of the whole vehicle is divided into two routes. One air source is connected to the 4th port of the two-position five-way valve 14, and the other air source is connected to the air inlet of the pressure reducing valve 18. When there is no air source at the 4th port of the two-position five-way valve 14, the air source of the whole vehicle enters the 1st port of the two-position five-way valve 14 through the pressure reducing valve 18, the stop valve 16, and the connecting air pipe 15. At this time, the 1st port of the two-position five-way valve is connected to the 22nd port, and the 22nd port is connected to the high-gear air pipe assembly 12. The air source is divided into two routes through the high-gear air pipe assembly 12. One route enters the auxiliary box cylinder through the high-gear air pipe Ⅰ12.1 and the high-gear air pipe Ⅱ12.2 for the auxiliary box to switch to high gear, and the other route enters the locking cylinder through the high-gear air pipe Ⅰ12.1 and the high-gear air pipe Ⅲ12.3 to lock the cylinder. The inner locking piston 11 extends backward under the action of air pressure, overcoming the spring force, so that the shift shaft 6 cannot be selected to the right in high gear, thereby realizing the 1 / reverse gear selection lock; when the 4th port of the 2-position five-way valve 14 is ventilated, the 1st port and 21st port of the 2-position five-way valve are connected, the 21st port is connected to the low gear air pipe 13, and the 22nd port is exhausted, there is no air in the locking cylinder, and the locking piston 11 in the locking cylinder returns to its position under the action of the spring force. At this time, there is no obstruction on the right side of the shift shaft 6, and the 1 / reverse gear lock is released in low gear, realizing the effect of high speed ratio and strong power in the first gear.

[0040] ④ The operating structure is simple and compact. Due to space limitations, the connecting air pipe 15 connecting the stop valve 16 and the two-position five-way valve 14, and the connecting space of the high-block air pipe Ⅰ12.1 and the high-block air pipe Ⅲ12.3 connecting the two-position five-way valve 14 and the locking cylinder are relatively limited. In order to avoid the problem of laborious and inconvenient installation caused by direct connection of air pipes in a small space, the present invention makes the small space connecting air pipe 15 and the high-block air pipe Ⅲ12.3 into disc-shaped air pipes, so as to realize the adjustability of the air pipes during the installation process, and the installation is labor-saving and convenient.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pneumatically controlled operating mechanism capable of locking the 1st / reverse gear position, characterized in that: It includes a small cover, a shift shaft assembly, a fan-shaped self-locking block, a driving pin, a shift dial, a shift arm, a shift shaft, a stop valve, a connecting air pipe, a two-position five-way valve, a high-speed air pipe assembly, a low-speed air pipe and a locking cylinder; The shift shaft assembly includes a shift connecting shaft, a shift spline sleeve and a shift shaft; The shift connecting shaft passes through the small cover; The shift spline sleeve, shift shaft, fan-shaped self-locking block, shift dial head, and shift selector arm are located in the small cover; The right end of the shift connecting shaft is fixedly connected to the left end of the shift spline sleeve as a whole, and the shift connecting shaft and the shift spline sleeve can only rotate axially in the small cover, and cannot move axially; The left end of the shift shaft is connected to the right end of the shift spline sleeve via a spline, and the shift shaft can rotate axially and move axially in the small cover; The fan-shaped self-locking block is provided with an axial hole, an axial through groove is provided in the axial hole, and an M groove is provided on the surface of the fan-shaped self-locking block, and the M groove includes a middle groove and protrusions located on both sides of the middle groove; The driving pin vertically passes through the shift shaft; The shift shaft and the driving pin pass through the shaft hole of the fan-shaped self-locking block, and the end of the driving pin is located in the axial through groove of the fan-shaped self-locking block; The shift head fixing sleeve is arranged outside the shift shaft; The gear selection arm is overlapped with the gear shift knob; The gear selection shaft passes through the small cover, and the end portion located inside the small cover is fixedly connected to the gear selection rotating arm; Port 1 of the stop valve is connected to the air source of the vehicle, and port 2 of the stop valve is connected to port 1 of the two-position five-way valve through a connecting air pipe. The top pin of the stop valve passes through a small cover and is located in the middle groove of the M groove of the fan-shaped self-locking block. The fan-shaped self-locking block rotates to make the top pin telescopically control the connection and disconnection of ports 1 and 2; The high-barrier air pipe assembly comprises a high-barrier air pipe I, a high-barrier air pipe II and a high-barrier air pipe III which are interconnected; Port 21 of the two-position five-way valve is connected to the low-speed air inlet of the auxiliary box cylinder through a low-speed air pipe, and port 22 of the two-position five-way valve is connected to the high-speed air inlet of the auxiliary box cylinder through high-speed air pipe I and high-speed air pipe II. Ports 31 and 32 of the two-position five-way valve are exhaust ports, and port 4 of the two-position five-way valve is a control port. When there is no air source at the four ports of the two-position five-way valve, port 1 is connected to port 22, and port 21 is connected to port 31. When the four ports of the two-position five-way valve are ventilated, port 1 is connected to port 21, and port 22 is connected to port 32. The locking cylinder comprises a cylinder body, a locking piston and an elastic reset member; The cylinder body is connected to the right end of the small cover, and is provided with a first chamber and a second chamber, a piston hole is provided between the first chamber and the second chamber, the first chamber is connected to the 22nd port of the two-position five-way valve through the high-blocking air pipe I and the high-blocking air pipe III, and the second chamber is connected to the small cover; The locking piston comprises a piston disc and a piston rod connected to the piston disc; The piston disc is located in the first chamber, and the elastic reset member and the gas provided by the 22nd port of the two-position five-way valve are located on both sides of the piston disc; When in low gear, the piston rod is located at the front side of the right end of the shift shaft through the elastic return member, allowing the shift shaft to move right, and the 1 / reverse gear lock is released. When in high gear, the piston rod is extended backward through the piston hole by the action of air pressure, preventing the shift shaft from moving right, and the 1 / reverse gear lock is released.

2. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: The connecting trachea and the high-barrier trachea III are disc-shaped trachea.

3. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: The small cover comprises a small cover end cover and a small cover shell; The left side of the small cover housing is fixedly connected to the small cover end cover, and the right side is fixedly connected to the cylinder body of the locking cylinder.

4. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 3, characterized in that: The shift spline sleeve is axially limited in the small cover end cover by a cylindrical pin.

5. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: The right end of the shift connecting shaft is welded to the left end of the shift spline sleeve.

6. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: The shifting head is elastically and firmly connected with the shifting shaft through an elastic pin.

7. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: The elastic return element is a return spring.

8. The gas-controlled operating mechanism capable of locking the 1st / reverse gear position according to claim 1, characterized in that: Also included is a pressure relief valve; A pressure reducing valve is also installed between the stop valve and the gas source of the whole vehicle.

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