JPS6123465Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic clutch type transmission device used in construction machinery, agricultural machinery, and other moving work vehicles.

Hydraulic clutch type transmissions have the advantage of being able to vary without engaging or disconnecting the main clutch, but since it is necessary to operate the gear shift lever to operate the hydraulic directional control valve device, the lever must be operated. The same thing happened. However, in recent years, hydraulic directional control valve devices have come to be constructed with electromagnetic valves in order to make the movement of the shift lever easier, or to enable button operation or automatic control to shift gears. This solenoid valve may directly control the pressure oil, or it may be used as a pilot valve to operate the spool of a separately provided main control valve, but the present invention is suitable for both of these cases. is also targeted.

That is, when using a solenoid valve for directional control, a certain problem occurs in the entire hydraulic circuit due to the nature of the solenoid valve, regardless of the method of use.

In other words, a solenoid valve uses a solenoid to move the valve by repelling or attracting it, so it is necessary to use a fairly large solenoid to generate enough force to move the valve, so it is important to use a solenoid valve with sufficient capacity. In this case, a large valve must be used that cannot be installed in the conventional manual control valve position, and the balance with the overall size of the device becomes unbalanced.

Using a suitably sized and attachable solenoid valve has the disadvantage that the flow rate in the circuit tends to be restricted at the position of the solenoid valve.

As a result, the anti-tangle brake, which was configured to set the pressure in the hydraulic circuit to zero when the gear is in the neutral state and perform braking by applying force to the shaft driven via the hydraulic clutch by a bullet, has been reduced to the back pressure. As a result, the back pressure becomes greater than the biasing force of the projectile, causing it to stop working, leading to accidents such as a parked work vehicle starting unmanned.

In addition, it also had the disadvantage that the hydraulic pump, solenoid valve, etc. became heated due to the generation of back pressure at the neutral shift position.

The present invention is designed to eliminate these drawbacks.

Based on the configuration of the embodiment shown in the accompanying drawings,
The configuration of the present invention will be explained in detail.

FIG. 1 is an overall side view of a tractor equipped with a hydraulic clutch type transmission according to the present invention.

An engine 2 is disposed inside a bonnet 1, and a front frame 3 is fixedly attached to the lower side surface of the engine 2 and projects forward. A front wheel 4 is supported on the front frame 3. A clutch housing 5 is fixed to the rear of the engine 2, and a transmission case 6 is fixed to the rear of the clutch housing 5. Further, a rear axle case 7 is fixed to the rear surface of the transmission case 6.

A rear axle housing 8 protrudes from both sides of the rear axle case 7, and a rear wheel 9 is supported by the rear axle housing 8.

At the rear of the rear axle case 7 is the PTO shaft 10.
protrudes, and a hydraulic case 14 is seated on the upper surface. Furthermore, a seat 15 is provided above the hydraulic case 14. A main transmission device consisting of a hydraulic clutch type transmission device and a sub-transmission device consisting of a sliding gear type transmission device are provided inside the transmission case 6, and a main transmission lever 12 for operating the main transmission device and a sub-transmission device are operated. A sub-shift lever 13 is provided on the upper surface of the transmission case. Furthermore, a PTO transmission which is a combination of a hydraulic clutch type transmission and a sliding gear type transmission is arranged inside the rear part of the rear axle case 7. A PTO main shift lever 16 for operating a PTO main transmission consisting of a hydraulic clutch type transmission is provided in parallel with the main shift lever 12, and a PTO sub-shift lever 11 of a PTO sub-transmission consisting of a sliding gear type transmission is operated by hydraulic pressure. It is provided near the case 14.

The two shift levers 12 and 16 of the hydraulic clutch type transmission device may be arranged on the dash board 1a at the rear end of the bonnet 1 as a push button switch operation method.

FIG. 2 is a side sectional view of the rear part of the rear axle case 7 showing a PTO transmission having the configuration of the present invention.

FIG. 3 is a sectional view of the rear part of the rear axle case, and in particular is a rear view showing the seal case 28, the anti-tangle brake device, and the relief valve W.

FIG. 4 is a side view showing the hydraulic directional control valve device V provided on the relief valve W.

FIG. 5 is a hydraulic circuit diagram of the present invention.

In FIG. 2, engine rotation is transmitted by a PTO transmission shaft 17 extending from the main clutch within the clutch housing 5.

A pair of hydraulic clutch devices 32 and 33 are fixedly installed back to back on the PTO transmission shaft 17, and a loosely fitted gear 18 is rotated via a friction plate that is connected and disconnected by the hydraulic clutch devices 32 and 33. 19 is
It is loosely fitted onto the PTO transmission shaft 17. The loose-fitting gear 19 further includes two loosely-fitting gears 22 and 23.
It is composed of continuous gears.

PTO shaft 1 arranged parallel to PTO shift shaft 17
0, there is a loosely fitted gear 18 on the PTO transmission shaft 17,
Two sets of loosely fitted gears 20 and 21 are loosely fitted and always mesh with 19, and two sets of sliding gears 25 and 26 that slide on splines are slidably provided at the rear of the gears, and a PTO transmission is provided at the rear thereof. 2 of the 3 loose gears on the shaft
A loosely fitting gear 24 that constantly meshes with the gear 3 is loosely fitted.
An inner gear 27 is carved into the loose fit gear 24.

Next, let us show the gear connections for each PTO gear in a 4-speed transmission.

The PTO gears 1st and 3rd are connected from the PTO gear shift shaft 17 through the engaged state of the hydraulic clutch 32 to the loosely fitted gear 18, and then from the loosely fitted gear 18 to the loosely fitted gear 20 on the PTO shaft. This is transmitted to Gear 21. Subsequently, the loosely fitted gear 21 reaches the loosely fitted gear 19 on the PTO transmission shaft 17 again. Here, the first speed and the third speed are separated, and the first speed is the rotation of the PTO shaft 10 from the loose fit gear 23 through the loose fit gear 24 on the PTO shaft, the internal gear 27, and the sliding gear 26.

The third speed is from the sliding gear 25 rather than the loosely fitted gear 22.
This results in rotation of the PTO shaft 10.

The PTO 2nd speed and 4th speed are transmitted from the PTO speed change shaft 17 to the loosely fitted gear 19 through the engaged state of the hydraulic clutch 33.
leading to. Here, the first gear coupled with the loosely fitting gear 23, the loosely fitting gear 24, and the sliding gear 26, the loosely fitting gear 22,
It is divided into a fourth speed connected to a sliding gear 25.

The selection of the hydraulic clutch devices 32 and 33 is performed by moving the solenoid valve 50 of the solenoid valve type hydraulic directional control valve device V by a switch operation using the PTO main shift lever 16, and the selection of the sliding gears 25 and 26 is performed by switching the PTO main shift lever 16. This is done by rotating the lever 11.

The hydraulic system for connecting and disconnecting the hydraulic clutch devices 32 and 33 will be explained.

The pressure oil pump 55 may also be used as a pump for main transmission, or may be provided separately. First, the pressure oil exits to the high pressure oil passage 45a shown in FIG.

The abnormal high pressure enters the high pressure relief valve W from the high pressure oil passage 46 and flows into the cylinder 47a of the valve body 47.
When the valve body 47 is pushed upward against the bullet 48, the pressure oil flows back into the rear axle case 7, which is a tank, from the drain oil passage through the low pressure relief 56 (not shown) without damaging the circuit.

Under normal conditions, the oil flows from the high pressure oil passage 46 into the oil passage of the relief valve lid body 51 shown in FIG. 4, and enters the solenoid valve from the high pressure port 57 of the solenoid valve 50. The solenoid valve 50 consists of 5 ports, P, M, A, B, and T in Fig. 5.
Consists of. When the PTO gear is at low speed, the pressure oil flowing into the high pressure port is connected to the oil passage 58 which is the A port, and reaches the oil passage of the seal case 28 from the oil passage 31 within the thickness of the rear axle case.

When the PTO main shift is high speed, the oil passage 59, which is the B port, passes through the oil passage 52, and then the oil passage 30 reaches the seal case. From the seal case 28, the hydraulic clutch 3
Enter cylinder 2,33. When the PTO main shift is in neutral, it is connected to the oil passage 60, which is the M port, and reaches the drain oil passage 49. Return oil port T is also oil path 7
1 to the drain oil passage 49.

In FIG. 3, a lubricating oil passage 29 extends from the drain oil passage 49 to the seal case, and lubricates the hydraulic clutch devices 32, 33.

The torsion brake device Y brakes by bringing a band 35 into close contact with the body portion 34 of the two loosely fitted gears 20 and 21 on the PTO shaft, and the hydraulic clutch device 32
33 is in the contact state, pressure oil flows into the oil passage 61 of the cylinder 53, the piston 36 is pushed upward against the bullet 37, and the band 35 is released and is in a non-braking state.

However, when the PTO main shift is in neutral, the high-pressure oil passage 46 communicates with the drain oil passage 49 through the electromagnetic valve type hydraulic directional control valve device V, so the hydraulic oil in the cylinder 53 escapes. Sorry, bullet 37
As a result, the piston 36 is pushed down, and the band 35 enters the braking state. This prevents tangling even if the friction plates of the hydraulic clutch devices 32, 33 are brought into contact due to the viscosity of the oil. As a result, the PTO shaft 10 does not rotate inadvertently, and when the PTO shaft 10 is used for traveling and shifting, it is possible to prevent an unattended start when the vehicle is stopped.

However, as described above, when the solenoid valve 50 is used in the oil passage directional control valve device V, the pressure in the high pressure oil passage 46 does not reach zero at the neutral position of the gear shift, and a back pressure of about 1 to 4 kg/cm ² is generated. It becomes. Since this back pressure remains in the cylinder 53 through the high pressure oil passage 46, the high pressure oil passage 45, and the high pressure oil passage 45b for the anti-tangle brake, the piston 36 does not return immediately and the brake band 35 becomes in a semi-braking state. , it will no longer be effective.

In order to eliminate this situation, a cut-off valve device X is provided between the pump 55 and the anti-entanglement brake device Y.

Cylinder 53 of anti-tangle brake device Y
is integrally formed with the support plate 62 of the PTO transmission unit, and is fastened to the rear plate 63 of the rear axle case with four long bolts 64.

This PTO transmission unit is assembled with a hydraulic clutch device and a gear device outside, assembled with a support plate 62 and bolts 64, inserted into the rear axle case 7 from the rear, and connected to the PTO transmission shaft 17 with a coupling. The face plate 63 is fastened to the rear surface of the rear axle case 7.

A cut-off valve device X is interposed between the support plate 62 and the rear plate 63 of the PTO transmission unit having such a structure.

A high-pressure oil passage 45b branching from the high-pressure oil passage 45a at the pump outlet shown in FIG. The connecting pipe 39
is in communication with the cut-off valve device X.

Cylinder 4 of valve body 40 of cut-off valve device
Pressure oil is flowing into 0c from the pressure oil port 44,
When the PTO main gear is in a position other than neutral, pressure acts on the valve body, and when the pressure exceeds 6 kg/cm ² , the valve body 40 is moved to the left against the bullet 41, and the oil port 43 is moved through the small diameter portion 40a. It flows into the cylinder 53 via the connecting pipe 38, pushes up the piston 36, and puts the brake band 35 in a non-braking state.

Conversely, when the PTO main gear is in the neutral state, the pressure of the pressure oil flowing through the connecting pipe 39 drops to 6.
Kg/cm ² or less, the force of the bullet 41 is superior, the valve body moves to the right, and the pressure oil in the cylinder 53 passes through the small diameter part 40 and flows through the oil drain port 42 to the rear axle case 7. run down. As described above, the cut-off valve device X is automatically switched by the valve body 40 and the bullet 41 by the pressure of the high-pressure oil passage 45. Therefore, the pressure inside the cylinder 53 also becomes 0, and the piston 36
is pressed by the bullet 37 and moves to put the brake band 35 in a braking state.

When the PTO main transmission is in the neutral state, the back pressure acting on the circuit is less than 6 kg/cm ² and there is no force that moves the valve body 40 of the cut-off valve device V to the left.

As described above, the present invention provides an anti-tangle brake that controls the tangle caused by the hydraulic clutch devices 32 and 33 in the neutral shift position of a hydraulic clutch type transmission operated by a solenoid valve type hydraulic directional control valve device V. The device Y is composed of a cylinder 53 that pushes in the non-braking direction by hydraulic pressure, and a piston 36 fitted in the cylinder 53 and constantly urged in the braking direction by the bullet 37, The oil passage 45 is communicated with the cylinder 53, and the pressure oil in the high pressure oil passage 45 is used as pilot pressure to apply pressure above a certain level to the high pressure oil passage 45 leading to the cylinder 53. A cut-off valve device X is provided which moves against the speed change and automatically switches, and in the shift position, the piston 36 is actuated by pressure oil to the non-braking side, and in the shift neutral position, the piston 36 is actuated to the braking side by the bullet 37. Therefore, it has the following effects.

First, when the hydraulic directional control valve device V is composed of an electromagnetic valve, the pressure of the pressure oil does not drop completely at the neutral shift position, and the cylinder that is pushed by the residual pressure is braked by the bullet. However, with the configuration of the present invention, the residual pressure can be completely brought to zero by the cut-off valve device X installed in the high-pressure oil path when the hydraulic directional control valve device V is at the neutral shift position. This makes it possible to reliably perform drag braking at the neutral shift position.

Second, in the case of the conventional anti-entanglement brake device disclosed in JP-A-52-114128, it is necessary to manually operate the anti-entanglement brake device in conjunction with the operation of the clutch pedal. In this case, this can be done instantaneously by automatically operating the cut-off valve device X installed in the high-pressure oil passage based on the switching of the hydraulic directional control valve device V. Therefore, this is particularly effective when the hydraulic directional control valve device V is composed of a solenoid valve or the like and it is difficult to connect it to a mechanical operating member such as a pedal or a gear shift lever.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the tractor, Fig. 2 is a sectional side view of the rear of the rear axle case of the tractor, and Fig. 3 is a rear view of the rear axle case, especially showing the seal case and the anti-tangle brake part. FIG. 4 is a plan view of the hydraulic directional control valve device, and FIG. 5 is a hydraulic circuit diagram of the present invention. V...Hydraulic directional control valve device, W...Relief valve device, X...Cut-off valve device, Y...Tangle prevention brake device, 10...PTO shaft, 17...
PTO transmission shaft, 32, 33...hydraulic clutch device, 35...brake band, 36...piston, 37...bullet, 40...valve body, 41...bullet, 53...brake cylinder.

Claims (1)

[Scope of utility model registration request] An anti-tangle brake device Y that controls the tangle caused by the hydraulic clutch devices 32 and 33 in the neutral shift position of a hydraulic clutch type transmission device operated by a solenoid valve type hydraulic directional control valve device V.
Cylinder 53 that pushes in the non-braking direction with hydraulic pressure
The piston 36 is fitted into the cylinder 53 and is constantly urged in the braking direction by the bullet 37, and the high pressure oil passage 45 of the hydraulic clutch type transmission is communicated with the cylinder 53. A cut-off valve device in which the valve element 40 moves against the bullet 41 and automatically switches when pressure above a certain level is applied to the high-pressure oil path 45, using the pressure oil in the high-pressure oil path 45 as pilot pressure. A hydraulic clutch type transmission device, characterized in that the piston 36 is actuated to the non-braking side by pressure oil at the shift position, and the piston 36 is actuated to the control side by a bullet 37 at the shift neutral position.