JP2558893Y2 - Operating device for steering mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for operating a side clutch and a side brake of a steering device using a hydraulic circuit of a hydraulic clutch type transmission.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique in which a gear is shifted by using a hydraulic clutch type transmission, and a side clutch and a side brake are operated by pressure oil to perform steering. For example, the technique disclosed in Japanese Utility Model Laid-Open No. 61-69548 is disclosed.

[0003]

In such prior art, pressure oil is supplied to a hydraulic clutch type transmission and a side clutch and a side brake by a dedicated hydraulic pump. Are installed in parallel, so that the load on the engine increases and space is required, and the number of parts such as piping increases,
It was also necessary to construct an oil passage, which was a high cost factor. Also, when turning at a high gear, it is very dangerous because the side clutch may suddenly start if the clutch is engaged. In some cases, power could not be transmitted smoothly.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, a steering mechanism including a side clutch capable of independently interrupting transmission of power from the hydraulic clutch type transmission to the left and right traveling devices and a side brake for further braking the traveling device on the power interruption side is provided by a hydraulic Hydraulic clutch type
Delay release with primary side connected to the hydraulic circuit of the transmission
And a hydraulic circuit for the side clutch and a hydraulic circuit for the side brake are connected to the secondary side of the delay relief valve 36. The primary pressure of the delay relief valve 36 is reduced to a low pressure. , Then automatic
An open valve 37 for increasing the pressure is provided , and a hydraulic control circuit for the side brake is provided with a sequence valve 33 for enabling the side brake to be operated after switching a steering control valve disposed in the hydraulic control circuit for the side clutch. Control valve 3
9 is provided with a variable pressure reducing valve 34 for increasing the operating oil pressure of the side brake in conjunction with the switching operation of No. 9.

[0005]

The above structure operates as follows. Rotate the main transmission lever to switch the switching valve 30
Switching, selecting and joining a hydraulic clutch type transmission to shift gears
At the time of shifting, the shift positions R1 and F
In the position between 1 and F2 and F3, pump pressure to hydraulic oil tank
There is a pump pressure open position that opens to the side
In response to the opening of the pump pressure during the shift period, the throttle valve 5
A pressure difference occurs around zero, and the open valve 37
Detects a certain pressure drop in the pressure circuit and switches to the open side.
The primary pressure is reduced to a low pressure,
When the valve 30 is moved and slid to the shift position, the open valve
37 is closed and pressure is increased automatically. The delay relief valve is actuated every time a gear is shifted to reduce a shock. When the side clutch lever is turned to make a turn, the hydraulic oil discharged from the delay relief valve is operated by the secondary relief valve. The direction control valve is guided to the side clutch to disconnect the turning-side clutch, and this pressure oil is increased to a predetermined pressure for operating the clutch by the pressure regulating valve. Next, the sequence valve 33 is switched so that pressure oil is supplied to the side brake to brake the turning side, and the operating oil pressure of the side brake is adjusted by a variable pressure reducing valve interlocked with the side clutch lever to increase the hydraulic pressure proportional to the amount of rotation. And the braking force can be adjusted. After the turn is complete,
Since the switch lever 43 is returned to the neutral position, the steering control valve 3
9 becomes the neutral position, and when the pressure on the secondary side drops at a stretch,
Abrupt change occurs, as shown in FIG.
Therefore, a pressure difference occurs before and after the throttle valve 50,
Since the open valve 37 is opened temporarily, the primary side
Of the shifting hydraulic clutch on the gear
The working pressure drops to this point. This makes it possible to
Even if you are driving, you can start smoothly
It is. Conversely, move the side clutch lever 43 to the right
The same effect is obtained when the camera is turned.

[0006]

Next, an embodiment will be described. FIG. 1 is a skeleton diagram of a transmission case, and FIG. 2 is a hydraulic circuit diagram of the operating device of the present invention. In FIG. 1, an input shaft 2 is horizontally mounted on an upper portion of a transmission case 1, and the transmission case 1
An input pulley 3 is fixed to one end of the outer input shaft 2,
A hydraulic pump P is attached to the other end, and the transmission case 1
A loose fitting gear 4 and a sliding gear 5 are externally fitted on the input shaft 2 inside, and the loose fitting gear 4 always meshes with a gear 7 fixed on the auxiliary transmission shaft 6, and the sliding gear 5 The toothed portion 4a of the loose fitting gear 4 and the gear 8 on the subtransmission shaft 6 are slid by the rotation of the speed change lever.
9 is selected and meshed to enable sub-shifting.

The gear 9 on the auxiliary transmission shaft 6 is further provided with a transmission single shaft 1
The gear 13 on the auxiliary transmission shaft 6 meshes with the gear 13 loosely fitted on the transmission single shaft 11, and meshes with the gear 13 loosely fitted on the transmission 1 and the gear 15 loosely fitted on the transmission double shaft 12. Is engaged with the gear 16 which is loosely fitted on the transmission double shaft 12. A first-speed hydraulic clutch F1 is interposed between the transmission single shaft 11 and the gear 14, a second-speed hydraulic clutch F2 is interposed between the transmission single shaft 11 and the gear 13, and a one-speed hydraulic clutch F2 is interposed between the transmission single shaft 11 and the gear 15. A third-speed hydraulic clutch F3 is interposed, and a reverse-speed hydraulic clutch R1 is interposed between the two-speed shift shaft 12 and the gear 16 to constitute a hydraulic clutch type transmission. The hydraulic clutch of FIG.

The gear 1 formed at the center of the transmission shaft 11
7, a gear 18 formed at the center of the transmission two shaft 12 meshes with a gear 20 fixed on the side clutch shaft 19, and a brake drum 22 is fixed at the end of the transmission two shaft 12 to constitute a parking brake. ing. Hydraulic side clutches SCL / SCR are formed between both side surfaces of the gear 20 and the gears 23L / 23R loosely fitted on the side clutch shaft 19, and the gear 2
3L / 23R meshes with gears 24aL / 24aR loosely fitted on the side brake shaft 21, and the gears 24aL / 24a
Hydraulic side brake S between R and side brake shaft 21
BL and SBR are formed, and the gears 24bL and 24bR loosely fitted on the side brake shaft 21 mesh with the gears 32L and 32R on the axles 31L and 31R, and the axles 31L and 31R.
Crawlers or running wheels can be driven by fixing drive sprockets or the like at both ends.

The hydraulic clutches F1, F2, F
The 3 · R1, the hydraulic side clutches SCL / SCR, and the hydraulic side brakes SBL / SBR are connected as in the hydraulic circuit shown in FIG. That is, the pressure oil from the hydraulic pump P is branched, and one of the pressure oils can be supplied to the hydraulic clutches F1, F2, F3, and R1 via the switching valve 30,
By switching the switching valve 30, the oil can be selectively supplied so that the power can be disconnected and connected, so that the speed can be changed. The other of the hydraulic oil from the hydraulic pump P is hydraulically transmitted through the delay relief valve 36. The oil is supplied to the side clutch side, but an open valve 37 is provided on the spool control side of the delay relief valve 36, and detects the pressure fluctuation of the hydraulic circuit on the shifting hydraulic clutch side to reduce the operating pressure of the hydraulic clutch. It is possible. And
The steering control valve 3 is provided on the secondary side of the delay relief valve 36.
9 is connected, the steering control valve 39 is formed of an electromagnetic valve, and is turned on / off by rotation of the side clutch lever 43.
It is switched by the switches 44L and 44R that are turned off.

An oil passage 45L is provided between the output ports A and B of the steering control valve 39 and the hydraulic side clutches SCL and SCR.
45R is connected, and a shuttle switching type pressure regulating valve 40 for setting the operation of the hydraulic side clutches SCL / SCR so as to be able to operate even at a low pressure is interposed between the oil passages 45L / 45R. The delay relief valve 3
6 and the sequence valve 33 in parallel with the steering control valve 39 on the secondary side.
And a variable pressure reducing valve 34, a switching valve 35, and hydraulic side brakes SBL / SBR are connected in series.
5 is a control valve that is switched by pilot oil pressure, and the pilot oil passages 46L and 46R are connected to the oil passages 45L and 45L.
It is communicated with each between the oil chamber side by sliding the spool 45R and switching valve 35 and sequence valve 33, variable
The variable pressure reducing valve 34 includes a side clutch lever 43 and a wire or the like.
Are linked together . Reference numeral 42 denotes a low-pressure relief valve for setting a lubricating oil pressure.

In such a configuration, the pressure oil from the hydraulic pump P rotates the main transmission lever to switch the switching valve 30 so that the transmission single shaft 11 and the transmission dual shaft 12 are rotated.
One of the upper hydraulic clutches F1, F2, F3, and R1 is selected and supplied with oil, and the clutch is brought into contact to perform gear shifting. This
The working hydraulic pressure of the hydraulic clutch is a delay relief valve
36 and an open valve 37. That is,
When the switching valve 30 is operated to slide, the switching valve 30
When the spool passes through the pump pressure open position , the pump pressure oil is communicated to the tank, so the primary side pressure drops to the position of the valley in FIG. 3 to lower the joining pressure. When the switching valve 30 is fixed to the shift position through the throttle valve 50 , the switching valve 30 passes through the throttle valve 50 and gradually delays.
The pressure oil of the primary side is immersed in the back chamber side of the relief valve 36.
The delay relief valve 36 at a constant pressure.
Raise so that it becomes a leaf valve. The secondary side pressure oil leaking at the constant relief pressure is sent to the steering control valve 39.
Here, when the side clutch lever 43 is tilted to the left, for example, the steering control valve 39 is switched, the oil supply port is connected to the output port A, oil is adjusted to a low pressure by the pressure regulating valve 40 through the oil passage 45L, and the hydraulic side clutch SCL Is operated, the transmission of power from the gear 20 to the gear 23L is cut off, and the aircraft turns to the left. And the pilot oil passage 46
The sequence valve 33 is opened from L, and the switching valve 35 is also switched at the same time, and the pressure oil is supplied from the secondary side of the delay relief valve 36 to the sequence valve 33, the variable pressure reducing valve 34, and the switching valve 35.
The hydraulic side brake SBL operates via the axle 31
The L side is braked to enable a steeper turn. At this time, the variable pressure reducing valve 34 is
3 is opened and closed with a pressure proportional to the amount of rotation, so that the braking force of the hydraulic side brake can be adjusted. After the end of the turn, the side clutch lever 43 is returned to the neutral position, so that the steering control valve 39 is in the neutral position,
A sudden change occurs in which the pressure on the secondary side decreases at a stretch, and as shown in FIG.
Since a pressure difference occurs before and after zero, the open valve 37 is temporarily opened, so that the operating pressure of the primary-side shift hydraulic clutch side hydraulic pressure is reduced to such an extent as to slip-engage. As a result, a smooth start can be achieved even when the vehicle is traveling at a high gear. Conversely, when the side clutch lever 43 is rotated rightward, the same operation is performed.

[0012]

[Effects of the Invention] The present invention is constructed as described above, and has the following effects. That is, the side clutch lever is turned to make a turn, and when the turn is completed, the operating pressure of the shift hydraulic clutch decreases and the clutch is in a half-clutch state. Can be turned safely, and the gear shifting can be performed smoothly, so that even if the side clutch is configured as a dog type, it can be flipped and the clutch can be engaged. There is no going away.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a transmission case.

FIG. 2 is a hydraulic circuit diagram of the operating device of the present invention.

FIG. 3 is a diagram showing the relationship between primary pressure and time.

[Explanation of symbols]

 P Hydraulic pump F1, F2, F3, R1 Hydraulic clutch SCL / SCR Side clutch SBL / SBR Side brake 30 Switching valve 33 Sequence valve 34 Variable pressure reducing valve 35 Switching valve 36 Delay relief valve 37 Open valve 39 Steering control valve

Claims (1)

(57) [Scope of request for utility model registration] 1. A steering mechanism comprising: a side clutch capable of independently interrupting transmission of power from a hydraulic clutch type transmission to left and right traveling devices; and a side brake for further braking the traveling device on the power interruption side. In a transmission of a work vehicle configured to be hydraulically operated, a hydraulic clutch
Relay connected to the hydraulic circuit of a hydraulic transmission
And the delay relief valve 36 is provided.
A hydraulic circuit for the side clutch and a hydraulic circuit for the side brake are connected to the secondary side of the valve. The primary pressure of the delay relief valve 36 is reduced to a low pressure.
An open valve 37 for dynamically increasing the pressure is provided , and a hydraulic valve for the side brake is provided with a sequence valve 33 for enabling the side brake after switching the steering control valve disposed in the hydraulic circuit for the side clutch. An operating device for a steering mechanism, comprising: a variable pressure reducing valve 34 that increases the operating oil pressure of a side brake in conjunction with a switching operation of a direction control valve 39.