JPH0344615Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention is used as a steering mechanism for crawler-type traveling equipment in construction machinery, agricultural machinery, etc.
This invention relates to the arrangement of a steering clutch sequence valve that performs sequence control of a hydraulic steering clutch device/hydraulic steering brake device.

(b) Prior art The same applicant has previously proposed a hydraulic steering clutch device/steering brake device as a steering mechanism in a transmission of a crawler type traveling device.
The technology related to the clutch sequence valve, which is interposed to operate both devices in sequence, was developed in the Jichi Kosho era.
The technique described in Japanese Patent No. 59-40591 is known to the public. Furthermore, as a technique for fitting and arranging a valve inside a rotating shaft, a technique such as that described in Japanese Utility Model Application Publication No. 153752/1983 is known.

(c) Problems to be solved by the invention In conventional hydraulic steering devices, the steering clutch device and the steering brake device are located on the shaft below the transmission case, and the steering brake device The steering clutch sequence valve, which switches the steering clutch device to the steering clutch disengagement state before braking, was installed with one end in contact with the automatic steering valve located on the top of the transmission case. .

However, since the steering clutch sequence valve does not need to be operated by the steering lever and is automatically switched by operating other manual steering valves or automatic steering valves, it is located at the top of the transmission case and close to the operator. It is a valve that does not need to be placed in any position.

Conventional steering clutch sequence valves have been configured so that the automatic steering valve moves hydraulically and is pushed by the automatic steering valve to perform the switching operation, so the valve case to accommodate it becomes longer in the axial direction, and the Since the valves were placed on the upper surface of the transmission case along with other valves, the upper surface of the transmission case became overcrowded and they were arranged in an overlapping manner, making the oil passage formation complicated.

By moving the steering clutch sequence valve to another location, the present invention simplifies the arrangement on the top surface of the transmission case and facilitates assembly.

In addition, by arranging the steering clutch sequence valve inside the steering shaft, the valve case can also be used for the shaft, and since it can be arranged compactly within the shaft, the pressure required to switch the clutch can be reduced. became smaller, and it became possible to set the switching pressure arbitrarily by changing the diameters of the biasing spring and the valve hole.

(d) Means for Solving the Problems The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

The steering mechanism of the crawler type traveling device consists of clutch pistons 12L, 12R and clutch friction plate 11.
The clutch piston 1 is composed of a hydraulic steering clutch device constituted by L and 11R, and a hydraulic steering brake device constituted by brake pistons 40L and 40R and brake friction plates 8L and 8R.
2L, 12R and brake piston 40L, 40R
A steering clutch sequence valve 10L, which connects and disconnects the steering clutch friction plates 11L, 11R and the steering brake friction plates 8L, 8R in sequence, in a configuration in which the steering clutch friction plates 11L, 11R and the steering brake friction plates 8L, 8R are arranged separately on the steering shaft 3. 1
0R is a sliding spool, and both left and right ends of the steering shaft 3 are fitted into valve holes drilled in a portion of the transmission case 9 that protrudes outside, and the outer periphery of the steering shaft 3 in the portion is fitted. Seal cases 7, 7 with oil passages perforated therein are fitted onto the outside.

(E) Embodiment The purpose and structure of the present invention are as described above. Next, the structure and operation of the embodiment shown in the attached drawings will be explained.

Fig. 1 is a power transmission system diagram of the transmission for crawler type traveling equipment of the present invention, Fig. 2 is also an oil path circuit diagram, and Fig. 3 is a front cross-section of the hydraulic steering device part which is the main part of the present invention. 4 is a front sectional view of the steering clutch sequence valve section showing the braking state of the steering brake device with the steering clutch device disconnected, and FIG. The device is shown in a front sectional view in an unbraked state.

Referring to FIG. 1, the overall power transmission system of the transmission device will be explained.

A V-pulley is fixed to the end of the input shaft 1, and rotation from the engine is transmitted to the pulley. Above the input shaft 1 is a transmission case 9L.
A pump shaft is extended to the outer wall portion protruding from the wall, and hydraulic pumps 26 and 26 for the steering clutch and steering brake are installed.
27 is attached.

A gear-sliding sub-transmission device is interposed between the input shaft 1 and the counter shaft 2, and the sub-transmission is performed in three stages: high, medium and low.

In the auxiliary transmission, the loose-fit gear 28 on the input shaft 1 and the fixed gear 32 on the counter shaft 2 are always in mesh for a low gear, and the loose-fit gear 30 and a fixed gear 35 are always in mesh for a high-speed gear. The sliding gear 29 meshes with the fixed gear 33 on the counter shaft 2 to obtain the middle gear. Furthermore, the sliding gear 29 is a loosely fitted gear 28, 3.
The sliding gear 29 also plays the role of engaging the input shaft 1 with the input shaft 1, and by the left-right movement of the sliding gear 29, three speeds of high, medium, and low speeds can be performed.

After being shifted to high, medium, and low by the sub-transmission device, the rotation is controlled by five sets of hydraulic clutch devices 16, 17, 18, 1 on three hydraulic clutch shafts 21, 22, 23.
The main transmission device constituted by 9 and 20 enables further gear changes.

The five sets of hydraulic clutch devices are configured to obtain each main shift speed by connecting two sets each.

First, the second reverse speed is obtained by connecting the hydraulic clutch devices 19 and 16, and the first reverse speed is obtained by connecting the hydraulic clutch devices 20 and 16.

Next, the first forward speed is obtained by connecting the hydraulic clutch devices 20 and 18, the second forward speed is obtained by connecting the hydraulic clutch devices 19 and 18, and the third forward speed is obtained by connecting the hydraulic clutch devices 20 and 17, Four forward speeds are obtained by connecting hydraulic clutch devices 19 and 17.

The rotation after shifting by the five sets of hydraulic clutch devices is transmitted through the gear 15a on the hydraulic clutch shaft 22 and the gear 15b on the hydraulic clutch shaft 23 to the gear 14 of the steering clutch device.

Left and right steering clutch friction plates 11L, 11R are configured on the boss portion of the gear 14, and after the steering clutch friction plates 11L, 11R cut off the power, the left and right steering brake friction plates 8L, 8R separate the left and right steering clutch friction plates 11L, 11R. Braking is then applied to make a turn with a smaller turning radius. The steering clutch friction plate 11L, 1
Steering clutch sequence valves 10L and 10R are necessary to sequentially connect and disconnect 1R and steering brake friction plates 8L and 8R.

After the power is connected/disconnected and braked on the steering shaft 3, the rotation is transmitted to the left and right final shafts 24L, 24R, and finally to the drive sprocket shaft 25.
R.25R drives a crawler type traveling device.

Next, the configuration of the hydraulic steering device on the steering shaft 3 will be explained with reference to FIG.

The transmission case 9 is constructed by combining the left and right transmission cases 9L and 9R into one vertical case, and an oil passage plate 5 is attached to the outer surface of the transmission case 9L. 9 and oil road plate 5
An oil channel is formed between the two. Also, an oil passage plate 4 is attached to the outer surface of the right transmission case 9R.
Pressure oil is sent to the steering brake device and steering clutch device on the right side.

A steering clutch case 45 is located in the center of the steering shaft 3.
is permanently installed. A fixed gear 14 is disposed on the outer periphery of the steering clutch case 45, and a gear 15a on the hydraulic clutch shaft 22 and a gear 15b on the hydraulic clutch shaft 23 are meshed with the fixed gear 14, so that the hydraulic clutch type main The rotation after being changed by the transmission is transmitted.

Steering clutch pistons 12L and 12R are fitted on the left and right sides of the steering clutch case 45,
The steering clutch pistons 12L, 12R are always urged toward the clutch engagement side by urging springs 13L, 13R. With this configuration, even when the engine is stopped and the steering clutch hydraulic pump 26 is stopped, the steering clutch is engaged and the upper parking brake device can perform braking.

Therefore, the steering clutch pistons 12L and 12R of the steering clutch device are configured to be pressed by pressure oil from both the steering clutch engagement side and the steering clutch disengagement side. The steering clutch pistons 12L, 12 are activated by pressure oil or by the biasing spring 13.
When R is pressed toward the steering clutch friction plates 11L, 11R, the rotation of the gear 14 is transmitted to the left and right clutch gears 42L, 42R.

Steering brake friction plates 8L and 8R are locked to the outer periphery of the boss portions of the clutch gears 42L and 42R.

The steering brake friction plates 8L, 8R are constructed by arranging wet multi-plate discs on the clutch gears 42L, 42R alternately with brake case side friction plates protruding from the transmission case side. , 6R, the steering brake pistons 40L and 40R are fitted into the innermost portions of the steering brake pistons 40L and 40R to perform braking.

Oil is supplied from the periphery of the brake case 6R to the steering brake friction plate 8L via the lubrication oil path a1 from the lubrication oil path a2 around the hydraulic clutch shaft 23.

In addition, a lubricating oil passage b1 is opened in the transmission case 9R to the right steering brake friction plate 8R, and the lubricating oil passage b1 is connected to the oil passage plate 4 and the transmission case 9L.
The lubricating oil is guided to the lubricating oil path b2 between the two, and drips onto the steering brake device 8R from the lubricating oil path b2.

In this configuration, the steering clutch sequence valves 10L and 10R are arranged inside valve holes bored at both ends of the steering shaft 3.

Next, the hydraulic circuit of the transmission of the present invention will be explained based on FIG.

As described above, the hydraulic pumps 26 and 27 are disposed at the portion where the other end of the input shaft in the upper part of the transmission case 9 protrudes from the transmission case 9. The hydraulic pump 26 supplies pressurized oil to the hydraulic clutch type transmission and the steering clutch system. Further, the hydraulic pump 27 supplies pressure oil to the steering brake device.

After the pressure oil discharged from the hydraulic pump 26 passes through the day relief valve DLV, it is controlled by the hydraulic control valves V1 and V2 of the hydraulic clutch type transmission and is transmitted to one of the hydraulic clutch devices 16, 17, 18. , hydraulic clutch devices 19 and 20 are selectively coupled to obtain two reverse speeds and four forward speeds.

Similarly, the pressure oil discharged from the hydraulic pump 26 is sent via a check valve to the oil passage 7a of the seal case 7 where the left and right steering clutch sequence valves 10L, 10R are arranged.

The pressure oil that has passed through the steering clutch sequence valves 10L, 10R from the oil passage 7a is supplied to the steering clutch engagement side of the steering clutch pistons 12L, 12R.

Pressure oil discharged from the hydraulic pump 27 is supplied to the automatic steering valve in the case of automatic steering using the steering sensor.
Hydraulic pilot type, controlled by ASV
Oil is sent to the switching valves PBL and PBR for manual operation and automatic steering, and the pressure oil is automatically switched to the switching valves PBL and PBR.
Switch between PBL and PBR. When automatic steering is not in effect, the pressure oil whose direction is controlled by manual steering valves HSL and HSR passes through the switching valves PBL and PBR after passing through the neutral position of automatic steering valve ASV.

Then, the pressure oil passes through the switching valves PBL and PBR,
The oil flows from the oil passage 7b of the seal case 7 into the oil passage 3c at the end of the steering shaft 3, and is switched by pushing the steering clutch sequence valves 10L and 10R.

The steering clutch sequence valve 10L, than the biasing spring of the steering brake piston 40L, 40R.
Since the biasing force of the biasing spring 5 of 10R is set to a small value, when the steering sequence valves 10L and 10R are switched to the state shown in FIG. 4, the steering clutch device is disconnected, and then the steering This shows the state in which the brake device is braking.

In FIG. 4, the oil passage 3c at the end of the steering shaft 3 is
Pressure oil flows into the steering brake pistons 40L, 40R, and first the steering brake pistons 40L, 40R flow into the steering brake pistons 40L, 40R.
Before moving 40R, the steering clutch sequence valves 10L and 10R are pushed in to switch the steering clutch pistons 12L and 12R to the steering clutch disengagement side. In this state, the pressure oil in the oil passage 7a for the steering clutch is sent through the land 10b into the oil passage 3b drilled in the steering shaft 3, and is sent to the disconnected side of the steering clutch pistons 12L and 12R. It is. The steering clutch piston 12L,
By applying pressure oil to the disconnection side of 12R, the steering clutch device switches to the disconnected state, and the sequence-controlled steering brake pistons 40L and 40R gradually apply braking.

At this time, the steering clutch piston 12
Return oil from the oil chamber on the steering clutch connection side of L and 12R is supplied to the steering clutch sequence valve 10L,
The bearing B of the steering shaft 3 is lubricated from the oil passage 10a of 10R through the oil passage 3d of the steering shaft 3.

In FIG. 5, the steering clutch device is shown in the engaged state and the steering brake device is shown in the non-braking state.

After the steering operation is completed, the manual steering valves HSL and HSR or the automatic steering valve ASV are switched to the neutral state in order to proceed straight, and the steering brake piston 40 is switched to the neutral state.
Since the oil supply to L and 40R is stopped, the steering brake is first released, the pressure in the oil passages 7b and 3c decreases, and the biasing force of the biasing spring S causes the steering clutch sequence valves 10L and 10R to be closed. returns to the position shown in FIG. 5, and the pressure oil in the oil passages 7a of the seal cases 7, 7 passes from the oil passage 10a through the oil passage in the hole in the biasing spring S to the oil passage 3a on the steering shaft 3. Therefore, the oil is sent to the steering clutch connection side of the steering clutch pistons 12L and 12R. This causes the steering clutch to be engaged.

Also, since a large load is applied to the bearing that supports the steering shaft when the clutch is engaged or disconnected, if necessary, the drain oil passage of the steering clutch sequence valve can be opened in the bearing of the steering shaft. Since the bearing B supporting the steering shaft 3 can be lubricated by introducing the drain oil of the steering clutch sequence valve, seizure of the bearing B can be avoided. This is possible.

(f) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, by installing the steering clutch sequence valves 10L and 10R inside the steering shaft 3, it is possible to eliminate the overcrowding on the upper surface of the transmission case where the valves were conventionally located, and to improve the oil passage. By simplifying the arrangement, processing and assembly can be simplified.

Second, the steering clutch sequence valve 10
By arranging L and 10R inside the steering shaft 3, the case of the valve is also used as the steering shaft, making it unnecessary, and the steering clutch sequence valve can be made smaller, making it easier to The switching pressure can also be reduced.

Third, the sequence control timing can be easily adjusted by removing the seal case 7 and replacing the biasing spring S, and can be changed according to the working conditions and the road surface condition. This is something that can be done.

Fourthly, the end of the steering shaft where the steering clutch sequence valve is disposed is a part supported by the bearing B, so it is a part that is less affected by bending or twisting of the steering shaft 3, and the spool The movement of the body is not obstructed.

[Brief explanation of the drawing]

Fig. 1 is a power transmission system diagram of the transmission for crawler type traveling equipment of the present invention, Fig. 2 is a hydraulic circuit diagram, and Fig. 3 is a front cross-sectional view of the hydraulic steering device, which is the main part of the present invention. , FIG. 4 is a front cross-sectional view of the steering clutch sequence valve section showing the braking state of the steering brake device with the steering clutch device disconnected, and FIG. 5 is a front sectional view of the steering clutch sequence valve section with the steering clutch device disconnected and the steering brake device is a front sectional view in a non-braking state. 3... Steering shaft, 6... Brake case, 8L,
8R...Steering brake friction plate, 9L, 9R...Mission case, 10L, 10R...Steering clutch sequence valve, 11L, 11R...Steering clutch friction plate, 12L, 12R...Steering clutch piston, 40L, 40R...Steering brake piston.

Claims (1)

[Scope of utility model registration request] The steering mechanism of the crawler type traveling device consists of clutch pistons 12L, 12R and clutch friction plate 11.
The clutch piston 1 is composed of a hydraulic steering clutch device constituted by L and 11R, and a hydraulic steering brake device constituted by brake pistons 40L and 40R and brake friction plates 8L and 8R.
2L, 12R and brake piston 40L, 40R
A steering clutch sequence valve 10L, which connects and disconnects the steering clutch friction plates 11L, 11R and the steering brake friction plates 8L, 8R in sequence, in a configuration in which the steering clutch friction plates 11L, 11R and the steering brake friction plates 8L, 8R are arranged separately on the steering shaft 3. 1
0R is a sliding spool, and both left and right ends of the steering shaft 3 are fitted into valve holes drilled in a portion of the transmission case 9 that protrudes outside, and the outer periphery of the steering shaft 3 in the portion is fitted. A hydraulic steering device characterized by externally fitting seal cases 7, 7 having oil passages therein.