JP3756767B2 - Shuttle device for traveling vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shuttle device for a traveling vehicle such as a tractor.
[0002]
[Prior art]
In a traveling vehicle such as a tractor, the transmission is equipped with a shuttle device in order to perform forward and backward movement efficiently and frequently.
The shuttle device is configured by providing a synchro clutch on the shuttle shaft and a forward / reverse gear that selectively engages the shuttle shaft by the clutch and transmits power to the shuttle gear shaft, and the clutch is a shift rod. Can be switched by moving a shift lever provided in
[0003]
[Problems to be solved by the invention]
Recently, due to an increase in demand for dairy utilities, the front loader mounting rate of tractors tends to increase, and the frequency of use of the shuttle shift is increasing. Further, as the vehicle weight and the engine rated speed increase, shuttle synchronization is required to have high synchronization capability.
In such a tendency to increase horsepower, even if the capacity of the synchro means is increased in order to facilitate synchronization of the synchro means of the clutch in the prior art, it is constrained by the forward / reverse gear and the shuttle gear shaft. There is a limit to the radial space, and it is difficult to increase the size, and there is a problem in terms of durability even if double cone sync is used.
[0004]
It is an object of the present invention to provide a shuttle device for a traveling vehicle that can solve such problems of the prior art.
According to the present invention, when the clutch is in a neutral state, the load is applied to the shuttle shaft by the load applying means, thereby assisting the synchronizing work of the synchronizing means, thereby facilitating the synchronizing of the synchronizing means and improving the durability. An object of the present invention is to provide a shuttle device for a traveling vehicle.
[0005]
[Means for Solving the Problems]
The first specific means for solving the problems in the present invention is that the shuttle shaft 2 is synchronized with the synchro clutch 3 and the clutch shaft 3 is selectively engaged with the shuttle shaft 2 to transmit power to the shuttle gear shaft 4. In a shuttle device for a traveling vehicle provided with forward and reverse gears 5 and 6 for transmission,
A load applying means 7 for applying a load to the shuttle shaft 2 when the clutch 3 is in a neutral state is provided.
[0006]
As a result, when the clutch 3 is changed from the forward rotation state or the reverse rotation state to the neutral state, a load is applied to the shuttle shaft 2 by the load applying means 7, so that the shuttle shaft 2 is forcibly decelerated and the clutch 3 synchronization means Can be easily synchronized.
The second specific means for solving the problem in the present invention is that the shuttle shaft 2 is synchronized with the synchro clutch 3 and the clutch shaft 3 is selectively engaged with the shuttle shaft 2 to transmit power to the shuttle gear shaft 4. In a shuttle device for a traveling vehicle provided with forward and reverse gears 5 and 6 for transmission,
A load applying means 7 for applying a load to the shuttle shaft 2 is provided between the shuttle shaft 2 and the transmission case 8 that supports the shuttle shaft 2 when switching of the clutch 3 from the forward rotation state or the reverse rotation state is started.
[0007]
As a result, when the clutch 3 starts to be switched from the forward rotation state or the reverse rotation state, a load is applied to the shuttle shaft 2 by the load applying means 7, so that the shuttle shaft 2 is forcibly decelerated and the synchronization means of the clutch 3 is synchronized. Synchronization is easy.
The third specific means for solving the problems in the present invention is that the clutch 3 can be switched by a shift lever 11 provided on the shift rod 10 in addition to the first or second specific means. The load applying means 7 is set to be operable when the shift rod 10 is moved to the neutral position.
[0008]
Thus, when the shift lever 11 is operated to switch the clutch 3, the load applying means 7 is also operated at the same time, so that the setting and operation of the assist operation timing of the load applying means 7 can be facilitated.
The fourth specific means for solving the problems in the present invention is that, in addition to any one of the first to third specific means, the load applying means 7 includes a pump 12 and a control valve 13 for controlling the discharge amount thereof. It is to have.
Thus, by controlling the discharge amount of the pump 12 by the control valve 13, it becomes possible to apply a load to the shuttle shaft 2 with a simple and compact configuration.
[0009]
A fifth specific means for solving the problems in the present invention is that, in addition to the fourth specific means, the pump 12 is a trochoid pump.
Thus, by controlling the discharge amount of the trochoid pump 12 by the control valve 13, it is possible to apply a load to the shuttle shaft 2 with a simple and compact configuration.
The sixth specific means for solving the problems in the present invention includes, in addition to the fourth or fifth specific means, the switching start of the clutch 3 from the forward rotation state or the reverse rotation state, and the pump 12 by the control valve 13. That is, the discharge amount control start is substantially matched.
[0010]
As a result, the shuttle shaft 2 can be stopped appropriately and promptly by the pump 12.
A seventh specific means for solving the problems in the present invention is that the load applying means 7 is constituted by a brake device in addition to any one of the first to third specific means.
As a result, a load is applied to the shuttle shaft 2 by the brake device, and the shuttle shaft 2 can be stopped appropriately and quickly.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 exemplify a transmission of an agricultural tractor. Reference numeral 17 denotes a flywheel connected to an engine, which transmits power to the travel propulsion shaft 19 via the main clutch 18, and the travel propulsion shaft 19. The PTO drive shaft 20 penetrating through is directly connected.
A main transmission 22 is provided between the traveling propulsion shaft 19 and a counter shaft 21 arranged in parallel therewith, and a shuttle shaft 2 is connected to the rear of the counter shaft 21 via a hydraulic clutch 23 to thereby change the main transmission. Later power can be transmitted and disconnected.
[0012]
A shuttle gear shaft 4 and a height shaft 24 are arranged in parallel with the shuttle shaft 2, the shuttle gear shaft 4 is loosely fitted to the PTO drive shaft 20, and the height shaft 24 is loosely fitted to the transmission shaft 25, Between the shuttle shaft 2 and the shuttle gear shaft 4, the shuttle device 1 for switching the traveling power between forward and reverse is disposed, and between the shuttle gear shaft 4 and the height shaft 24, the high / low speed change device 30 is disposed. .
Reference numeral 26 denotes a part of a creep reduction device provided between the height shaft 24 and the transmission shaft 25, and the transmission shaft 25 is connected to a bevel pinion shaft 27.
[0013]
Reference numeral 28 denotes a hydraulic clutch for connecting / disconnecting power from the PTO drive shaft 20 to the PTO transmission shaft 29.
In the shuttle device 1, the shuttle shaft 2 has a double synchromesh type (synchronous) type clutch 3, and the clutch 3 selectively engages with the shuttle shaft 2 to transmit power to the shuttle gear shaft 4. Forward and reverse gears 5 and 6 are provided.
The forward gear 5 meshes with the gear 34 on the shuttle gear shaft 4, the reverse gear 6 meshes with the back gear 35, and the back gear 35 meshes with the gear 36 on the shuttle gear shaft 4.
[0014]
The rotation of the gears 34, 36 is transmitted to the high speed gear 38 of the high / low speed transmission 30 via the gear 37, or the rotation is transmitted to the low speed gear 39 of the high / low speed transmission 30 via the gear 36.
When the clutch 3 starts to move the shifter 41 between the forward and reverse gears 5 and 6 in one direction, the synchronizer key 42 pushes the synchronizer ring 43 against one cone portion of the forward and reverse gears 5 and 6 at its end. The rotation of the coupling 44 and the synchronizer key 42 that rotate together with the shuttle shaft 2 starts to be transmitted to the synchronizer ring 43 and the forward and reverse rotation gears 5 and 6 by the frictional force generated in the part. The shifter 41, the synchronizer key 42, the synchronizer ring 43 and the like constitute a synchronizer.
[0015]
The shifter 41 can be reciprocated by a shift lever 11 provided on the shift rod 10, and the shift rod 10 is supported by the mission case 8 and is pushed by operating means 45 also supported by the mission case 8. .
The operating means 45 includes a lever shaft 46 that is rotatably supported by the mission case 8, a lever 47 that is attached to the lever shaft 46 and has a tip engaged with the shift rod 10, and an upper end of the lever shaft 46. And an operation arm 48 and the like connected to each other.
[0016]
The shift rod 10 can be positioned by the positioning means 49 at the forward rotation position, the reverse rotation position, and the neutral position between the two positions. The shift rod 10 has a neutral position recess 10a, a forward rotation position recess 10b, and a reverse rotation position recess. 10c is formed.
Further, the shift rod 10 is formed with recesses 10d, 10e, and 10f. A neutral detection switch 51 and a back detection switch 52 are disposed in the mission case 8 so as to oppose them. The forward / reverse state can be detected.
[0017]
The rear end of the shuttle shaft 2 protrudes rearward from the rear end bearing 54 and the cover 55, and load applying means 7 for applying a load to the shuttle shaft 2 when the clutch 3 is in a neutral state is provided at the rear end. An actuating means 56 for operating the load applying means 7 is provided between the load applying means 7 and the shift rod 10.
The load applying means 7 has a pump 12 and a control valve 13 for controlling the discharge amount. In the embodiment, the pump 12 is a hydraulic trochoid pump, and may be another fluid pressure pump.
[0018]
An inner rotor 58 of the pump 12 is fixed to the shuttle shaft 2, and a casing 59 having an outer rotor is fixed to the transmission case 8 together with the cover 55, and the transmission oil in the transmission case 8 is sucked into the suction port of the casing 59. The suction pipe 60 is connected, and the control valve 13 is disposed at the discharge port 61.
The control valve 13 includes a valve main body 62 that is screwed to the casing 59 to form a discharge passage 62a, and a ball (valve element) 63 and a spring 64 that are disposed in the valve main body 62.
[0019]
An operating rod 65 that pushes the ball 63 is inserted into the valve body 62, and the operating rod 65 can be brought into contact with the operating portion 10g formed on the shift rod 10, These constitute the operating means 56.
The control valve 13 pushes the operating rod 65 and pushes the ball 63 against the spring 64, thereby connecting the discharge port 61 to the discharge passage 62a (open circuit state), and discharging the discharge oil. When the operating rod 65 is opposed to the operating portion 10g to release the pushing and the ball 63 is brought into contact with the valve seat in the valve main body 62, the discharge port 61 is closed ( Closed circuit state), a load is applied to the inner rotor 58 to stop its rotation.
[0020]
The relationship between the positioning recesses 10a, 10b, 10c of the shift rod 10 and the operating portion 10g is as follows. As shown in FIG. 6, the operating portion 10g is positioned between the forward rotation position recess 10b and the reverse rotation position recess 10c. The both ends of the actuating portion 10g substantially coincide with the inner ends of the recesses 10b and 10c. Both ends of the operating portion 10g and the inner ends of the recesses 10b and 10c may be slightly separated from each other, or may overlap.
FIG. 5 shows the pressure increase characteristics at the time of shuttle shift, the A line indicates the pressure of the trochoid pump 12, the B line indicates the pilot pressure of the hydraulic clutch 23, the C line indicates the clutch pressure of the hydraulic clutch 23, and the range D indicates The time of a substantially neutral state is shown.
[0021]
When shifting the tractor from forward to reverse or from reverse to forward, the operating means 45 is operated to move the shift rod 10 in the axial direction. When the shift of the shift rod 10 causes the clutch 3 to start switching from the forward rotation state or the reverse rotation state to the neutral state side, first, the pilot pressure supply to the hydraulic clutch 23 is stopped, and the hydraulic clutch 23 is turned off. At substantially the same time, the operating portion 10g starts to release the pushing against the operating rod 65, and closes the control valve 13 to control (stop) the amount of oil discharged from the pump 12, thereby the trochoid. The pressure of the pump 12 rises rapidly, and the rotational energy of the shuttle shaft 2 is absorbed as a reaction force to brake the shuttle shaft 2.
[0022]
When the clutch 3 is shifted to the target shift side, the operating rod 65 is also pushed out from the operating portion 10g, the control valve 13 is opened, the load on the shuttle shaft 2 is released, and the pilot pressure to the hydraulic clutch 23 is released. Supply is resumed, the hydraulic clutch 23 is gradually brought into a contact state, the clutch pressure rises, power is transmitted from the counter shaft 21 to the shuttle shaft 2 via the hydraulic clutch 23, and the positive pressure is transmitted from the shuttle shaft 2 via the clutch 3. It is transmitted to the reverse gears 5 and 6.
As is apparent from the speed change operation, the speed change operation of the shuttle device 1 and the start of control of the discharge amount of the pump 12 are set to substantially coincide with each other in order to stop the shuttle shaft 2 properly and promptly by the pump 12. ing.
[0023]
When shifting by shifting the shifter 41, in the prior art, the relative rotational speed synchronized only by the synchronizer ring 43 is closed at the neutral point that is the passing point at the time of shifting, and the trochoid pump 12 is closed. As a circuit, the shuttle shaft 2 is braked. As a result, the relative rotational speed that must be synchronized by synchronization can be halved, so that high durability can be ensured even with a smaller-sized synchronization means.
In addition, this invention is not limited to the said embodiment, A various deformation | transformation can be carried out. For example, as the load application means 7, a brake device such as a band brake or a disk brake may be provided on the shuttle shaft 2 instead of the pump 12.
[0024]
【The invention's effect】
According to the present invention described in detail above, when shifting the shuttle device 1, a load can be applied to the shuttle shaft 2 by the load applying means 7, and the shuttle shaft 2 is forcibly decelerated to easily synchronize the synchronizing means. This makes it possible to increase the horsepower without increasing the size of the synchro means and improve the durability.
[Brief description of the drawings]
FIG. 1 is an overall cross-sectional side view showing an embodiment of the present invention.
FIG. 2 is a sectional side view of the shuttle device.
FIG. 3 is a sectional rear view of the same part.
4 is a cross-sectional view taken along line XX of FIG.
FIG. 5 is a graph showing boost characteristics at the time of shuttle shift.
FIG. 6 is an explanatory diagram for explaining the operation timing of the pump.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shuttle device 2 Shuttle shaft 3 Clutch 4 Shuttle gear shaft 5 Forward rotation gear 6 Reverse rotation gear 7 Load applying means 8 Mission case 10 Shift rod 11 Shift lever 12 Pump 13 Control valve

Claims (3)

Reverse rotation gear the shuttle shaft, transmits the synchronous type clutch which is switched by a moving operation of the shift rod, the power to the shuttle gear shaft engages selectively engaged to the shuttle shaft by the switching operation of the clutch In a shuttle device for a traveling vehicle provided with
A pump driven by the shuttle shaft is provided, a control valve for controlling the discharge amount of the pump is provided on the discharge side of the pump, and an operating rod is provided between the valve body of the control valve and the shift rod. In a state where the shift rod is moved so as to selectively engage the forward / reverse gear with the shuttle shaft, the operating rod is pushed by the shift rod and the valve body is pushed by the operating rod. It is configured to allow the discharge of pressure oil from the pump, and when the shift rod is moved to move the clutch to the neutral state, the operation rod is controlled to control the pump discharge amount so that a load is applied to the shuttle shaft . A shuttle device for a traveling vehicle, wherein the shift rod is provided with an operating portion for releasing the pushing force on the valve body . Reverse rotation gear the shuttle shaft, transmits the synchronous type clutch which is switched by a moving operation of the shift rod, the power to the shuttle gear shaft engages selectively engaged to the shuttle shaft by the switching operation of the clutch In a shuttle device for a traveling vehicle provided with
A pump driven by the shuttle shaft is provided, a control valve for controlling the discharge amount of the pump is provided on the discharge side of the pump, and an operating rod is provided between the valve body of the control valve and the shift rod. In a state where the shift rod is moved so as to selectively engage the forward / reverse gear with the shuttle shaft, the operating rod is pushed by the shift rod and the valve body is pushed by the operating rod. It is configured to allow the discharge of pressure oil from the pump, and when the shift rod is moved to move the clutch to the neutral state, the operation rod is controlled to control the pump discharge amount so that a load is applied to the shuttle shaft. provided the operating unit to release the pressing against the valve body to the shift rod, and the start of a change over from forward rotation state or reverse state of the clutch, the pump discharge amount control start and substantially scratch by the control valve Shuttle apparatus of the traveling vehicle, characterized in that it is. The shuttle device for a traveling vehicle according to claim 1 , wherein the pump is a trochoid pump .

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