CN205013630U - Auxiliary start -stop circulation mechanism of fluid gravity - Google Patents

Abstract

The utility model relates to a start-stop circulation mechanism assisted by fluid gravity, comprising: a driving mechanism connected by a fork lever and a toggle mechanism, the driving mechanism can drive the drive gear to rotate forward and reversely; the toggle mechanism includes a slidingly arranged dial Two shift fork rods are arranged on the shift rod, and the two shift fork rods are respectively located outside the two ends of the drive gear; one end of the drive shaft is provided with a screw rod, and the threaded sleeve connecting the curved rod is threaded on the screw rod, and the curved rod is provided with a contact One side of the contact is provided with a fluid deflection device, the fluid deflection device is provided with two fluid tanks, the middle shaft of the two fluid tanks is connected, and the two fluid tanks are connected together. The fluid deflection device is moved to make it rotate along the rotating shaft, and a protrusion is also provided on the driving rod, and the protrusion is connected with the stop mechanism. The soft rope connected to the fluid box at one end of the downward trend is gradually tightened, and then the taut soft rope will gradually generate a pulling force on the block on the other side, and pull the shift lever to the direction of the downward slope.

Description

A fluid gravity-assisted start-stop cycle mechanism

technical field

The utility model relates to a transmission conversion mechanism, in particular to a start-stop circulation mechanism assisted by fluid gravity.

Background technique

The transmission conversion mode of modern power mechanism is mostly carried out by means of frequency converter to control the motor. The frequency converter controls the speed of the motor and controls the steering of the motor, which makes the speed output of the motor to the transmission mechanism extremely flexible. However, the common frequency converter has insufficient voltage compensation for the motor when outputting low frequency, and the torque boost of the motor is not enough, resulting in a decrease in the output torque of the motor and unstable load capacity. Therefore, in the case of low-speed operation and high power requirements, it is still necessary to use a reducer. When the power output by the motor is decelerated by the reducer, the torque can be increased. However, in the case of frequent cut-off of output power and frequent reversing, this type of device can only be realized by frequent start and stop of the motor, and frequent forward and reverse switching. Long-term use is not conducive to the normal operation of the motor. Therefore, it is necessary to design a set of mechanical transmission mechanism to realize the functions of frequent reversing and frequent cut-off of the output power under the condition of continuous and stable operation of the motor and reducer.

Contents of the invention

The utility model overcomes the shortcomings of the prior art and provides a fluid gravity-assisted start-stop cycle mechanism driven by fluid potential energy.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a fluid gravity-assisted start-stop circulation mechanism, including: a drive mechanism and a toggle mechanism connected by a shift fork lever, which is characterized in that,

- the drive mechanism can drive the drive gear to rotate forward and reverse;

- the toggling mechanism includes a slidably set lever, on which two fork levers are arranged, and the two fork levers are respectively located outside the two ends of the drive gear;

One end of the drive shaft is provided with a screw, and the threaded sleeve connected to the bent rod is threaded on the screw, and a contact is provided on the curved rod; a fluid deflection device is provided on one side of the contact, and the fluid deflection The device is equipped with two fluid tanks, the middle rotating shafts of the two fluid tanks are connected, and the two fluid tanks are connected together. The fluid tanks are not filled with fluid, and the contacts can move the fluid deflection device to make it Rotating along the rotating shaft, the driving lever is also provided with a projection, and the projection is engaged with the stop mechanism.

In a preferred embodiment of the present invention, the two ends of the driving rod are respectively slidably socketed on the corresponding sleeves.

In a preferred embodiment of the present invention, one end of the soft rope is connected to one of the fluid boxes, and then passes through the holes on the two sets of blocks in sequence, and finally the other end of the soft rope is connected to the other fluid box.

In a preferred embodiment of the utility model, the part of the soft rope connected to one end of the fluid deflection device that is inclined to fall is preferentially tightened.

In a preferred embodiment of the present invention, the fluid can flow in series in the two fluid tanks.

In a preferred embodiment of the present invention, the tilted end of the fluid deflection device is located on the trajectory of the end of the contact along the movement of the screw, and the trajectory of the movement of the end of the contact along the screw is lower than that of the fluid deflection device. of the upper surface.

In a preferred embodiment of the present invention, the distance between the two shift fork rods is greater than the axial length of the driving gear.

In a preferred embodiment of the present invention, the driving gear sliding key is arranged on the driving shaft, and the moving distance of the driving gear on the sliding key of the driving shaft is the distance between the first gear and the second gear axial distance.

In a preferred embodiment of the present invention, the driving mechanism includes a first gear and a second gear that can respectively mesh with the driving gear, the driving gear is slidably arranged on the driving shaft, the first gear and the second gear The two gears rotate in opposite directions;

The first gear is coaxially connected with a transmission gear, and the transmission gear meshes with the second gear.

In a preferred embodiment of the present invention, the stop mechanism includes a stop rod with a wedge-shaped head at one end and a fixed plate, the wedge-shaped head of the stop rod protrudes outside one surface of the fixed plate, and the stop rod also One end of the spring protrudes from the other side of the fixed plate, and the two ends of the spring are respectively fixed on the fixed plate and the stop bar; the wedge-shaped head includes a wedge-shaped surface and a right-angled surface, and the right-angled The plane is parallel to the axis of the gear lever.

In a preferred embodiment of the utility model, the fixing plate is fixedly connected with one of the sets.

In a preferred embodiment of the present invention, a handle is provided at the end of the stop rod on the stop mechanism.

The utility model solves the defects in the background technology, and the utility model has the following beneficial effects:

(1) Through the action of the toggle mechanism, the position of the driving gear can be changed between the first gear and the second gear, which plays the role of changing the meshing object of the driving gear. At the same time, because the first gear and the second gear rotate in opposite directions, Ensure that the drive shaft changes direction of rotation each time the drive gear changes meshing objects.

(2) The rotation direction of the drive shaft and the toggle direction of the toggle mechanism just form a linkage structure. When the drive gear meshes with the first gear, the toggle mechanism is driven by the drive shaft so that the toggle mechanism has the ability to turn the drive gear to the second gear. The tendency and power of the gear, and the final drive gear is separated from the first gear, and the gravity potential energy change generated by the fluid flow in the fluid deflection device connected to the lever is driven to mesh with the second gear; otherwise, when the drive gear meshes with the second gear, the dial The actuator will cause the drive gear to move in reverse.

(3) On the one hand, the structure of the feather key can ensure that there is a clamp limit between the drive gear and the drive shaft along the circumference of the drive shaft, so that the drive gear will not move relative to the drive shaft along the circumference; on the other hand, the drive gear can Sliding along the axial direction of the drive shaft ensures that the drive gear moves between the first gear and the second gear.

(4) The two fork levers are respectively located on both sides of the drive gear, and the drive gear can move axially along the drive shaft under the drive of the lever.

(5) The set block can limit the movement posture of the lever, and the soft rope can limit the deflection range of the fluid deflection device, and then the movement range of the lever is also limited to ensure that the lever will not deviate excessively left and right, only to ensure that the drive It is sufficient for the gears to change the meshing distance between the first gear and the second gear.

(6) When the driving gear meshes with the first gear, the fluid box close to the first gear tilts down, and the screw sleeve is driven away from the first gear by the screw, and then the contact moves the fluid box on the side close to the second gear, which is tilted up , and press down the upward-inclined fluid tank, at this time, the fluid will be filled with fluid in the unfilled space in the depressed fluid tank, and the other fluid tank will become upward-inclined. Change and drag, the driving gear is disengaged from the first gear first, and then meshed with the second gear; after the above process is completed, the second gear drives the driving gear to reverse, and then the screw sleeve also moves in the reverse direction, so the contact at this time Press down the tilting fluid box and perform circular movements in sequence.

(7) During the left and right movement of the fork lever, the two fork levers continuously push the drive gear to move left and right along the drive shaft to change the meshing objects.

(8) The rotating shaft in the middle of the fluid deflection device ensures that the fluid tanks on both sides rotate symmetrically along it.

(9) The fluid in the fluid deflection device is not full. Always ensure that the fluid tank after tilting down will be filled with fluid, and the fluid tank that is tilting up will only be partially filled with fluid, so that the fluid can easily flow in the fluid deflection device. And drive the soft rope to pull the cover block.

(10) When the fluid deflection device goes over the horizontal position and inclines toward one end, the soft rope connected to the fluid tank at one end of the downward trend is gradually tightened, and then the taut flexible rope will gradually generate tension on the block on the other side, and pull the lever toward its downtilted side.

(11) The structure of the screw driving the screw sleeve, and then the screw sleeve provides the power source for the toggle mechanism. Since the rotation direction of the screw is related to the meshing object of the drive gear, the movement direction of the screw sleeve is related to the rotation direction of the drive shaft. The direction of rotation of the drive shaft is controlled by the toggle mechanism; thus, the above-mentioned process forms a cyclic motion process that influences each other, and the toggle mechanism and the drive mechanism continuously affect the continuous cycle control.

(12) The distance between the two shift fork rods is greater than the axial length of the drive gear, which can provide inertial buffering for the reverse movement of the drive gear.

(13) The distance between the two shift fork rods is greater than the axial length of the drive gear, and the length longer than the drive gear is the margin of the distance between the two shift fork rods relative to the length of the drive gear. Due to the existence of the above margin, the fluid deflection device When the upper surface is in a horizontal state, neither of the two fork levers will be blocked by the driving gear, and the upper surface of the fluid deflection device only needs to rely on inertia when it crosses its horizontal state.

(14) The transmission gear is coaxial with the first gear, and the second gear meshes with the transmission gear, realizing the reverse rotation of the first gear and the second gear.

(15) The trajectory of the contact is a horizontal straight line, and the trajectory of the contact is located near the upper surface of the fluid deflection device in a horizontal state, so that as long as the fluid tank is in an upward tilt state, the contact will definitely push upward along its trajectory the fluid tank and press it down.

(16) The center position of the upper surface of the fluid deflection device is lower than the distance from one end, and the two ends of the upper surface of the fluid deflection device are higher than the distance from one end. When the contact is at the center of the upper surface of the fluid deflection device, it is just close to the top In this way, as long as the contact moves to any one of the two ends of the upper surface of the fluid deflection device, the fluid tank at that end can be pressed down to ensure that the fluid tank is constantly swayed by the contact and drives the driving rod to move.

(17) The handle can pull up the stop lever on the manual stop mechanism, so that the bump blocked by the right-angled surface on the manual stop mechanism can be released from the restraint, and the lever can continue to move left and right. As long as the mechanism is not pulled up, it can only Do single-period exercises.

(18) The position set by the manual stop mechanism can block the bump at the position where the drive gear is just between the first gear and the second gear, and the drive gear is disengaged at this time.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a three-dimensional structure diagram one of a preferred embodiment of the present utility model;

Fig. 2 is the three-dimensional structure diagram two of the preferred embodiment of the present utility model;

Fig. 3 is a three-dimensional structure diagram of the stop mechanism of the present utility model;

In the figure: 1, the first gear, 2, the second gear, 3, the driving gear, 4, the driving shaft, 5, the feather key, 6, the transmission gear, 7, the driving lever, 8, the fork lever, 9, the cover block , 10, screw rod, 11, screw sleeve, 12, bent rod, 13, sleeve hole, 14, soft rope, 15, contact, 16, fluid deflection device, 17, fluid tank, 18, rotating shaft, 19, stop mechanism, 20, stop rod, 21, spring, 22, wedge-shaped head, 23, wedge-shaped surface, 24, right-angled surface, 25, projection, 26, handle, 27, fixed plate, 28, bolt locking device.

detailed description

The utility model is described in further detail now in conjunction with accompanying drawing and embodiment, and these accompanying drawings all are simplified schematic diagrams, only illustrate the basic structure of the utility model in schematic mode, so it only shows the formation relevant to the utility model.

As shown in Figure 1, Figure 2 and Figure 3, a fluid gravity-assisted start-stop cycle mechanism includes: a drive mechanism and a toggle mechanism connected by a fork lever 8,

- The driving mechanism includes a driving gear 3 capable of meshing with the first gear 1 and the second gear 2 respectively, the driving gear 3 is slidably arranged on the driving shaft 4, and the first gear 1 and the second gear 2 rotate in opposite directions;

-The toggling mechanism includes a sliding lever 7, and two fork levers 8 are arranged on the lever 7, and the two fork levers 8 are respectively located outside the two ends of the drive gear 3; the drive gear 3 can be driven by the lever 7 along the The drive shaft 4 moves axially.

One end of the drive shaft 4 is provided with a screw rod 10, and the screw sleeve 11 connected to the bent rod 12 is threaded on the screw rod 10, and the screw rod 10 drives the structure of the screw sleeve 11, and then the screw sleeve 11 provides a power source for the toggle mechanism. The direction of rotation is related to the meshing object of the drive gear 3, so the direction of motion of the screw sleeve 11 is related to the direction of rotation of the drive shaft 4, and the direction of rotation of the drive shaft 4 is controlled by the toggle mechanism; During the cycle movement process, the toggle mechanism and the drive mechanism continuously affect the continuous cycle control.

The curved rod 12 is provided with a contact 15; one side of the contact 15 is provided with a fluid deflection device 16, and the fluid deflection device 16 is provided with two fluid tanks 17, and the middle device 18 of the two fluid tanks 17 is connected and arranged, and the fluid deflection device 16 in the middle The device 18 ensures that each of the fluid tanks 17 on both sides rotates symmetrically along it.

The two fluid tanks 17 are connected together, the fluid tanks 17 are filled with fluid, and the contact 15 can move the fluid deflection device 16 to rotate along the device 18 . Fluid can flow in series between the two fluid tanks 17 . The fluid in the fluid deflection device 16 is not full, and the fluid tank 17 after the inclination is guaranteed to be full of fluid at all times, and only a part of the fluid tank 17 that is tilted up will be filled with fluid, so that the fluid can easily flow in the fluid deflection device 16 , and drive soft rope 14 to pull cover block 9.

Through the action of the toggle mechanism, the position of the driving gear 3 can be changed between the first gear 1 and the second gear 2, which plays the role of changing the meshing object of the driving gear 3. At the same time, due to the rotation of the first gear 1 and the second gear 2 The direction is opposite to ensure that the drive shaft 4 changes the direction of rotation each time the drive gear 3 changes the meshing object.

The rotation direction of the drive shaft 4 and the toggle direction of the toggle mechanism just form a linkage structure. When the drive gear 3 meshes with the first gear 1, the toggle mechanism is driven by the drive shaft 4 so that the toggle mechanism has the ability to turn the drive gear 3 to The inclination and power of the second gear 2, and finally the drive gear 3 breaks away from the first gear 1, and the fluid flow in the fluid deflection device 16 connected on the driving rod 7 generates the change of gravity potential energy to drive and mesh with the second gear 2; otherwise, the drive gear When 3 meshes with the second gear 2, the toggle mechanism will cause the driving gear 3 to move in reverse.

During the left and right movement of the shift lever 7, the shift fork lever 8 continuously pushes the drive gear 3 to move left and right along the drive shaft 4 through the two shift fork levers 8 to change the meshing object.

The two ends of the driving rod 7 are respectively slidably sleeved on the corresponding sleeves 9 . The cover block 9 can limit the movement posture of the driving rod 7, and the soft rope 14 can limit the deflection range of the fluid deflection device 16, and then the movement range of the driving rod 7 is also limited, so as to ensure that the driving rod 7 will not deviate excessively from left to right, It is only necessary to ensure that the driving gear 3 can change the meshing distance between the first gear 1 and the second gear 2 .

One end of the soft rope 14 is connected to a fluid box 17, and then passed through the sleeve holes 13 on the two sets of blocks 9 in turn, and finally the other end of the soft rope 14 is connected to another fluid box 17. When the fluid deflection device 16 is tilted towards one end beyond the horizontal position, the flexible rope 14 connected to the fluid tank 17 at one end of the downward tendency is gradually tightened, and then the tightened flexible rope 14 will gradually generate pressure on the sleeve block 9 on the other side. pulling force, and pull the lever 7 to the direction of its downward tilting side.

The part of the soft rope 14 connected to one end of the fluid deflection device 16 inclined to fall is preferentially tightened. When the driving gear 3 meshes with the first gear 1, the fluid box 17 close to the first gear 1 tilts down, and the screw sleeve 11 is driven away from the first gear 1 by the screw 10, and then the contact 15 moves to the side close to the second gear 2. One fluid box 17 of incline, and the fluid box 17 of inclination is pressed down, and this moment, fluid will be filled with fluid in the unfilled space in the fluid water tank that presses down, and six another fluid box 17 becomes to incline, and above-mentioned process During the process, the lever 7 is dragged by the change of the tightness of the soft rope 14, and the driving gear 3 is first disengaged from the first gear 1, and then meshed with the second gear 2; after the above process is completed, the second gear 2 drives the driving gear 3 Reversing, then the screw sleeve 11 also moves in the reverse direction, so the contact 15 now presses down the fluid box 17 which is tilted up, and moves in a circular motion sequentially.

The tilted end of the fluid deflection device 16 is located on the trajectory of the end of the contact 15 along the movement of the screw 10, the trajectory of the end of the contact 15 along the movement of the screw 10 is lower than the upper surface of the fluid deflection device 16, and the movement trajectory of the contact 15 is a level straight line, and the trajectory of the contact 15 is in the vicinity of the upper surface of the fluid deflection device 16 in a horizontal state, so as long as the fluid tank 17 is in an upwardly inclined state, the contact 15 will definitely push the upwardly inclined fluid tank 17 along its trajectory, and Press it down.

The distance between the two shift fork rods 8 is greater than the axial length of the drive gear 3 , which can provide inertial buffering for the reverse movement of the drive gear 3 . The distance between the two shift fork rods 8 is greater than the axial length of the drive gear 3, and the length longer than the drive gear 3 is the margin of the distance between the two shift fork rods 8 relative to the length of the drive gear 3. Due to the existence of the above margin, the fluid When the upper surface of the deflection device 16 is in a horizontal state, the two fork levers 8 will not be blocked by the drive gear 3 , and the upper surface of the fluid deflection device 16 only needs to rely on inertia when it crosses the horizontal state.

The sliding key 5 of the driving gear 3 is arranged on the driving shaft 4 , and the moving distance of the driving gear 3 on the sliding key 5 of the driving shaft 4 is the axial distance between the first gear 1 and the second gear 2 . On the one hand, the structure of the feather key 5 can ensure that there is a clamp limit between the drive gear 3 and the drive shaft 4 along the circumference of the drive shaft 4, so that the drive gear 3 will not move relative to the drive shaft 4 along the circumference; The driving gear 3 can slide along the axial direction of the driving shaft 4 to ensure that the driving gear 3 moves between the first gear 1 and the second gear 2 .

The first gear 1 is coaxially connected to the transmission gear 6, the transmission gear 6 meshes with the second gear 2, the transmission gear 6 is coaxial with the first gear 1, and the second gear 2 meshes with the transmission gear 6, realizing the first gear 1 and the second gear The reverse rotation of the second gear 2.

The center position of the upper surface of the fluid deflection device 16 is recessed by one end distance, and the two ends of the upper surface of the fluid deflection device 16 are higher than one end distance. 16 upper surface, so as long as the contact 15 moves to either end of the two ends of the upper surface of the fluid deflection device 16, the fluid tank 17 at this end can be pressed down to ensure that the fluid tank 17 is constantly swayed by the contact 15, and the driving lever 7 is driven sports.

The end of stop bar 20 on stop mechanism 19 is provided with handle 26, and handle 26 can pull up stop bar 20 on stop mechanism 19, and the projection 25 that is blocked by right-angled surface 24 on stop mechanism 19 can break away from restraint like this, dial Bar 7 just can continue to move left and right, as long as do not pull up this mechanism just can only do single cycle motion. The position provided by the stop mechanism 19 can block the protrusion 25 at the position where the drive gear 3 is just located between the first gear 1 and the second gear 2 , and the drive gear 3 is disengaged at this time.

Stopping mechanism 19 comprises a stop bar 20 and a fixed plate 27 that one end has wedge-shaped head 22, and fixed plate 27 is connected with a sleeve block 9, and the wedge-shaped head 22 of stop bar 20 stretches out fixed plate 27 one face outsides, and stop bar 20 is other One end of the spring 21 protrudes from the other side of the fixing plate 27 . The two ends of the spring 21 are respectively fixed on the fixing plate 27 and the stop bar 20 .

As shown in Figure 1, the projection 25 can only cross the wedge-shaped surface 23 on the stop mechanism 19 from the left side of the stop mechanism 19 to the right side of the stop mechanism 19, but the projection 25 cannot cross the stop mechanism from the right side of the stop mechanism 19. The right-angled surface 24 on 19 reaches the left side of the stop mechanism 19 .

Bending bar 12 is provided with a bolt locking device 28 at its turning point, and the part parallel to drive shaft 4 of bending bar 12 can be inserted in the inner hole of bolt locking device 28, and slides in its inner hole, and bolt locking device 28 The bolts on the top are screwed in and screwed out to control the tightness; by adjusting the relative position of the curved rod 12 and the bolt locking device 28, the position adjustment of the curved rod 12 to the shift fork rod 8 can be realized, so as to adjust the shifting of the shift fork rod 8 to the driving gear. timing.

The driving rod 7 can only move along the axial direction of the driving rod 7 itself under the restriction of the cover block 9, but the driving rod 7 cannot rotate along the axial direction of the driving rod itself in the cover block 9, so that the movement on the driving rod 7 is ensured. The shift fork lever 8 can not turn to, and it has also ensured that the shift fork lever 8 can be moved to the drive gear 3 on its motion track.

The above is inspired by the ideal embodiment of the utility model, and through the above description, relevant personnel can make various changes and modifications within the scope of not deviating from the technical idea of the utility model. The technical scope of this utility model is not limited to the content in the description, and must be determined according to the scope of the claims.

Claims (10)

1. A fluid gravity-assisted start-stop cycle mechanism, comprising: a drive mechanism and a toggle mechanism connected by a shift fork lever, characterized in that, - the drive mechanism can drive the drive gear to rotate forward and reverse; - the toggling mechanism includes a slidably set lever, on which two fork levers are arranged, and the two fork levers are respectively located outside the two ends of the driving gear; One end of the drive shaft is provided with a screw, and the threaded sleeve connected to the bent rod is threaded on the screw, and a contact is provided on the curved rod; a fluid deflection device is provided on one side of the contact, and the fluid deflection The device is equipped with two fluid tanks, the middle rotating shafts of the two fluid tanks are connected, and the two fluid tanks are connected together. The fluid tanks are not filled with fluid, and the contacts can move the fluid deflection device to make it rotate along the axis of rotation, A bump is also provided on the shift lever, and the bump is engaged with the stop mechanism. 2. A fluid gravity-assisted start-stop cycle mechanism according to claim 1, characterized in that: the two ends of the driving rod are respectively slidably socketed on the respective corresponding blocks. 3. A fluid gravity-assisted start-stop circulation mechanism according to claim 2, characterized in that: one end of the soft rope is connected to one of the fluid tanks, and then passes through the sleeve holes on the two sets of blocks in sequence, and finally soft The other end of the rope is connected to another said fluid tank. 4 . The fluid gravity-assisted start-stop cycle mechanism according to claim 3 , wherein the soft rope part connected to one end of the fluid deflection device tilted down is preferentially tightened. 5 . The fluid gravity-assisted start-stop circulation mechanism according to claim 1 , wherein the fluid can flow in series in the two fluid tanks. 6 . 6. A fluid gravity-assisted start-stop cycle mechanism according to claim 1, characterized in that: the tilted end of the fluid deflection device is located on the trajectory of the end of the contact along the movement of the screw, and the contact The trajectory of the head end along the movement of the screw is lower than the upper surface of the fluid deflection device. 7 . The fluid gravity-assisted start-stop cycle mechanism according to claim 1 , wherein the distance between the two shift fork rods is greater than the axial length of the driving gear. 8 . 8. A fluid gravity-assisted start-stop circulation mechanism according to claim 1, characterized in that: said drive mechanism comprises a first gear and a second gear respectively capable of meshing with a drive gear, and said drive gear is slidably arranged On the drive shaft, the first gear and the second gear rotate in opposite directions; The first gear is coaxially connected with a transmission gear, and the transmission gear meshes with the second gear. 9. A fluid gravity-assisted start-stop cycle mechanism according to claim 8, characterized in that: the drive gear feather key is arranged on the drive shaft, and the drive gear moves on the drive shaft feather key The distance is the axial distance between the first gear and the second gear. 10. A fluid gravity-assisted start-stop circulation mechanism according to claim 1, characterized in that: said stop mechanism comprises a stop rod with a wedge-shaped head at one end and a fixing plate, and the wedge-shaped head of said stop rod extends out of one surface of the fixed plate, the other end of the stop rod is sleeved with a spring protruding out of the other surface of the fixed plate, and the two ends of the spring are respectively fixed on the fixed plate and the stop rod; The wedge-shaped head includes a wedge-shaped surface and a right-angled surface, the right-angled surface is parallel to the lever axis.