JPS638062A - Brake system of rotary body - Google Patents

Abstract

PURPOSE:To enable one hydraulic shovel body to cope with various types of working field and improve economy by selectably using an automatic brake method and a dynamic brake method by means of hydraulic locking. CONSTITUTION:When a hydraulic shovel is used for an earthwork machine, a switch 15 is kept opened. And, an electromagnetic selector valve 12 is not exited and the connection between oil passages 24, 25 which are the operating circuits of a rotation motor 4 is shut off. In this condition, by operating the operating lever 21 of a pilot valve 20 switching over a hydraulic selector valve 3, the rotation motor 4 is rotated or stopped, to effect a braking performance. When the hydraulic shovel is used for the purpose of cargo working, a rotating operation is carried out with the switch 15 in a closed condition. Thereupon, the electromagnetic selector valve 12 is excited and a pilot oil passage 30 is connected to a pilot oil chamber. And, the operating lever 21 is operated to rotate the upper rotary body.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a planing stem for an upper rotating body of a construction/loading machine, in which the upper rotating body is configured to be able to rotate relative to the lower traveling body. It is.

Conventional technology Hydraulic excavators can be used for various types of work, such as by replacing the front attachment, they can be used for earth and sand excavation work like a backhoe, or for cargo handling work like a talam shell or crane. It has a wide range of uses. Its greatest feature is that by fully rotating the upper revolving body, it is possible to move the position of tip tools, such as buffs, clamshell packets, crane hooks, etc., to any position within the revolving work range. , The point is that accurate positioning is easy, but there is also a brake operation method for a rotating body for positioning depending on the type of work,
Different braking characteristics are also required for each vehicle. That is, when the hydraulic excavator is used as a backhoe as shown in Fig. 2, the swing operation lever is operated to make the desired left and right turns, and when the tip tool comes close to the predetermined position, the swing operation lever is returned to the neutral position 1. On the other hand, when using it as a lane as shown in Fig. 3, the same applies to the case of Taramsiel. , from the tip of the front attachment to the hook block 3 by the winch 35 via the wire rope 36.
In a crane that performs work by raising and lowering the crane, when the revolving body attempts to stop with the same hydraulic brake force as in the case of the backhoe, the hook block 37 of the crane will cause a pendulum movement due to inertia force, and the crane will move to a predetermined position. Since it is not possible to position the hook block 37 or clamshell, etc., in this case, even when the swing operation lever is set to neutral, no braking torque is generated in the swing hydraulic motor, or only a small amount of braking is generated. A dynamic brake device is provided that can generate only torque and adjust the braking force as necessary using separate means. In addition, no matter which type of front attachment is installed, a parking swing brake is required to prevent the upper swing structure from turning due to external force for safety when the machine is not in use.

In order to meet the above requirements, the following methods have been used in the past. That is, for example, when the backhoe packet 34 shown in FIG. 2 is used to excavate and load earth and sand, the hydraulic circuit shown in FIG. 4 is suitable, and the hydraulic circuit shown in FIG.
When the upper rotating body is driven to rotate the upper rotating body, and then the hydraulic switching valve 3 is set to the neutral position, the oil passages 24 and 25 are closed, but the upper rotating body forcibly rotates the rotating motor 4 due to its inertia. At the same time, a hydraulic brake torque is generated in the swing motor 4 due to the lock pressure, but in order to prevent this value from becoming excessive, a relief valve 9 is installed between the oil passages 24 and 25. Since the rotational inertia of the upper revolving body is automatically decelerated by a constant brake torque, the rotational inertia of the upper rotating body is automatically decelerated by a constant brake torque. and comes to a halt. In addition, when the machine is parked or when equipped with a parking brake to maintain the turning position, the turning operation is controlled by hydraulic pressure on the brake disc 6 fixed to the output shaft of the turning motor 4, as shown in the electro-hydraulic circuit of FIG. A spring-loaded hydraulic release type brake cylinder 13' that is activated after automatic stopping by the brake is arranged, and a pilot pump is installed in the release oil chamber of the brake cylinder 13' according to the opening and closing of a switch 15 installed near the driver's seat. 2
A tank 31 or an oil path for the hydraulic source pressure oil is led through an electromagnetic switching valve 12 that closes or allows the hydraulic source pressure oil to flow. Therefore, before operating the hydraulic excavator, first close the switch 15 and connect the power source 16 to the break selector valve 12.
The electromagnetic switching valve 12 is switched and the pressure oil of the pilot pump 2 flows into the release oil chamber of the brake cylinder 13', so the brake disc 6 can rotate freely, so the swinging operation of the hydraulic excavator becomes normal. When the swing operation is temporarily interrupted or the machine is stopped, when the switch 15 is opened or the drive of the pilot pump 2 is stopped, the release oil chamber of the brake cylinder 13° communicates with the tank 31. A braking force is applied to the brake disc 6 by the force.

In this type of parking brake device, the switch 15 must be operated each time the upper revolving structure needs to be stopped, which may be cumbersome depending on the work, or even when the upper revolving structure is turning. However, the switch 15 may be erroneously opened, causing not only damage to the machine but also danger, so in recent years, a further improved circuit as shown in FIG. 6 has been adopted. That is, in the figure, since the hydraulic switching valve 3 for operating the swing motor is switched, when pilot pressure acts on any of the pilot oil chambers, the pilot pressure oil passes through the shuttle valve 14 and closes the pressure switch 32, thereby closing the pressure switch 32. atS communicates with the electromagnetic switching valve 12, and when the pilot pressure stops acting on the pilot oil chamber of the hydraulic switching valve 3, the hydraulic switching valve 3 returns to the neutral position and the pressure switch 32 is opened, and the timer 33 operates. Several seconds later, that is, after the upper revolving structure has completely stopped, the tm switching valve 12 is de-energized and the brake cylinder is activated.

On the other hand, during cargo handling work as illustrated in Fig. 3, in the circuit shown in Fig. 4.5.6 described above, when the hydraulic switching valve 3 is set to neutral upon completion of the swinging operation, a strong hydraulic brake is automatically applied. As a result, the suspended load shakes and normal work cannot be carried out.As a conventional example to deal with this, the hydraulic circuit and brake device are partially changed. In the neutral position of the valve 3', oil passages 24.25, which are the operating circuit of the swing motor 4, communicate internally, and a check valve 10 for replenishment is connected between the oil passages 24.25.
．． 10 degrees, but no relief valve is provided, or even if provided, a relief valve (not shown) set at a very low pressure is devised to operate. Therefore, when the upper revolving body is started and the hydraulic switching valve 3' etc. is set to the neutral position, the swing motor 4 is rotated by the inertia of the upper revolving body, but the discharged oil is discharged from the oil passage 24. Since the brake torque flows almost freely through the neutral position communication path of the hydraulic switching valve 3' or the low pressure relief valve, no brake torque is generated in the swing motor 4, or only a small amount is generated.On the other hand, the suspended load does not shake significantly. Since it is necessary to stop the upper swing structure at a predetermined position, a spring release hydraulically actuated brake cylinder 13 is separately installed on the brake disc 6 fixed to the swing motor output shaft as shown in the figure, and the brake cylinder 13 of the spring release hydraulic type is installed as shown in the figure. A dynamic brake is provided which brakes the brake disc 6 by supplying pressure oil from the master cylinder 18 to the hydraulic oil chamber of the brake cylinder 13 by depressing the torque pedal. When applying the parking brake, depress the brake pedal 17 and press the brake disc 6.
The button 19, which holds the position of the brake pedal 17 in the braked state, is pushed in and locked.

Problems to be Solved by the Invention When replacing the front attachment of a hydraulic cylinder and using it for excavation and earthwork work or cargo handling work, as mentioned above, the required swing braking performance is different, and therefore, the required swing braking performance is different at the same work site. If there is a specific type of work to be carried out, it is best to bring in multiple hydraulic excavators with swing brake performance suitable for each purpose, or else use a hydraulic excavator that requires modification and adjustment each time but is not suitable for a small work site. However, the economic and time losses are large.

In view of these points, the present invention makes simple changes to the hydraulic circuit of a single hydraulic excavator, and provides a revolving body equipped with a selection switch that allows the user to freely obtain swing braking performance for both earthwork work and cargo handling work. The aim is to realize a brake system for

Means for Solving the Problems The means of the present invention taken to realize the above-mentioned brake system are as follows: (a) A system is installed in the middle of the oil passage that communicates the inflow and outflow oil passages of the pressure oil for operating the swing motor. The passage is open and a communication valve is installed that closes when signal pressure is applied to the pilot oil chamber.The pilot oil chamber of the communication valve is normally supplied with pressure oil from a hydraulic source such as a pilot pump during operation. When energized by closing a switch near the seat, the shuttle valve takes out the higher pressure oil of the pilot pressure oil that leads to the two viroft oil chambers of the hydraulic switching valve for operating the swing motor. In addition to providing an electromagnetic switching valve that switches and guides A brake device is provided that applies braking force to the upper brake disc, and that has a lock button that can mechanically hold the position of the brake pedal in a state where braking force is applied to the brake disc.

When using a backhoe for earthwork work, leave the switch near the driver's seat open, and the communication valve installed between the swing motor operation circuits will be closed, so the swing motor operation circuit will be closed. When the hydraulic switching valve is operated to apply rotational force to the rotating body, and then the hydraulic switching valve is placed in a neutral position, the hydraulic motor generates a strong braking torque corresponding to the set pressure of the relief valve generated in the operating circuit.

When used as a thrusting machine, if the switch is closed, the pilot oil chamber of the communication valve communicates with the pilot oil chamber of the hydraulic switching valve for the swing motor via the shuttle valve. When the hydraulic switching valve for the swing motor is turned to the right or left in this state, the communication valve closes each time, so the high pressure oil from the hydraulic switching valve flows from the high pressure side oil path to the low pressure side oil path of the swing motor operating circuit. When the hydraulic switching valve is placed in the neutral position, the pilot pressure in the pilot oil chamber of the hydraulic switching valve has disappeared, so the communication valve opens and the swinging operation is performed normally. Since the two oil passages flowing in and out of the motor are in communication with each other, no hydraulic brake torque is generated in the swing motor.Furthermore, in order to freely brake the upper swing structure in this state, it is necessary to adjust the brake pedal in the driver's cab while adjusting the brake pedal. To apply the parking brake, depress the brake pedal and operate the lock button at that position.

Embodiment FIG. 1 is an electro-hydraulic circuit diagram showing an embodiment of the present invention. In Figure 1, 1 is the main pump that generates high-pressure oil that is the power source for the hydraulic excavator, and 2 is the main pump l.
A pilot pump is driven together with the pump. The oil discharged from the main pump 1 maintains a specified pressure range and flows through the oil path 22 into the pressure-operated hydraulic switching valve 3, which is operated by operating the swing operating lever 21. When biloft pressure is generated in the pilot oil passage 28 or 29 from the pilot valve 20, the left or right position is switched to E or H, and high-pressure oil is sent to the swing motor 4 through the oil passage 24 or 25 to drive the swing motor 4. However, the return oil passes through the oil passage on the opposite side, the switching passage of the hydraulic switching valve 3, and returns to the tank 31. When in neutral, the oil passages 24 and 25 are each independently closed, and the high pressure oil from the main pump 1 is transferred to the hydraulic switching valve 3.
It flows into the tank 31 through the oil passage 23 through the passage at the neutral position of , or branches off midway and flows into another hydraulic switching valve. Furthermore, the fact that a relief valve 9.9' and a check valve 10.10' are provided in the middle of the oil passage communicating with the oil passage 24.25, which is the operating circuit of the swing motor 4, is similar to that for conventional hydraulic excavators. It is exactly the same as the swing operation circuit and maintains the protection and operation reliability of the swing motor 4, but in addition to this, in the present invention, the communication oil passage is always open in the middle of the other communication oil passage, A communication valve 1 that closes when signal pressure is applied to the pilot oil chamber, and a switch 15 near the driver's seat connects the pilot oil chamber of the communication valve 11 to the pressure of the pilot pump 2 when the pilot oil chamber 16 is not energized. Shuttle valve I4 that guides oil through oil passages 27, 38, closes the oil passage 27 when the switch 15 is closed, and takes out only the high pressure side of the pilot oil passages 28, 29 from which the biloft pressure of the pilot valve 20 is derived. An electromagnetic switching valve 12 is provided that allows the oil passage 30 connected to the outlet port of the oil passage 38 to communicate with the oil passage 38 . The brake disc 6 fixed on the output shaft of the swing motor 4 is also equipped with a brake cylinder 13, and braking force is applied by pressure oil from a master cylinder 18 that is linked to the operation of the brake pedal 17. brake pedal 1
The braking force is adjusted depending on the magnitude of the pressing force when stepping on the button 7.

Further, a fan-shaped lock 39 that rotates together with the brake pedal 17 and has a plurality of lock grooves on its outer periphery is provided.
The brake disc 6 is also provided with a lock button 19 that can lock and hold the lock slope 39 at the position of the brake pedal 17 where an appropriate braking force is applied by the action of the brake cylinder 13. In addition, 5 is a reducer directly connected to the output shaft of the swing motor 4, and 7 is the reducer 5.
8 is a swing pinion fixed to the output shaft end of the rotating body, and 8 is a swing gear fixed to the lower rotating body, and 26 is a swing pinion that connects the pressure oil of the pilot pump 2 to the pilot valve. 20.

The operation of the present invention having the above circuit and configuration will be explained.

First, when using the hydraulic bell as a normal earthmoving machine, open the switch 15. Then, the electromagnetic switching valve 12 will not be energized and will maintain the A position, so the pressure oil of the pilot pump 2 will not flow. The oil flows into the pilot oil chamber of the communication valve 11 through the oil passage 27, the A position passage of the electromagnetic switching valve 12, and the pilot oil passage 3B, and the communication valve 11 is switched from the 2 position to the C position, and the operating circuit of the swing motor An oil road 24.25
communication is cut off. Therefore, when attempting to rotate or stop the swing motor 4 by operating the operating lever 21 of the biloft valve 20 and switching the hydraulic switching valve 3 in this state, it is completely different from the swing operation of a conventional hydraulic excavator. Demonstrates the same turning brake performance.

Next, when using the hydraulic excavator for cargo handling work or similar purposes, turn the excavator with the switch 15 closed. Then, the electromagnetic switching valve 12 will be energized and switched from the A position to the Open position, so that the oil The passage 27 is closed and the pilot oil passage 30 is closed! It communicates with the pilot oil chamber of the communication valve 11 via the opening position passage of the break switching valve 12 and the pilot oil passage 38 . In this state, operate the operating lever 21 to
When a signal pressure is generated at 8 or 29, the hydraulic switching valve 3
At the same time, the high-pressure oil of the main pump 1 flows into the oil passage 24 or 25.
The viroft pressure in either pilot oil passage 28 or 29, whichever is higher, passes through shuttle valve 14 to pilot oil passage 30.
38 etc., the communication valve 11 is switched from the 2nd position to the C position, and as a result, the oil passages 24 and 25 are no longer communicated with each other, so the swing motor is started and the upper rotating structure is turned. Furthermore, when the operating lever 21 is set to neutral while the upper revolving structure is turning,
The biloft pressure in the pilot valve 20 disappears and the pilot oil passages 28 and 29 communicate with the tank 31, so the hydraulic switching valve 3 returns to position 1, and the high pressure oil from the main pump 1 flows into the oil passage 24 or 25. does not flow in, and at the same time, the nuclear oil channel 24
．． 25 are closed independently, but at the same time, the viroft oil passage 38 also communicates with the tank 31, so the communication valve 11
returns to the second position, the oil passages 24 and 25 are brought into communication via the second position passage of the communication valve 11, and the swing motor 4, that is, the upper swing structure continues to swing freely.

During cargo handling work, in order to apply an appropriate braking force to the upper revolving structure and cause it to decelerate or stop, it is sufficient to brake by gradually depressing the brake pedal F, and,
To apply the turning brake continuously for parking or other purposes, press the brake pedal 17 appropriately and press the lock button 1.
9 into the lock groove of the lock plate 39 and press the brake pedal 17. Note that the electromagnetic switching valve 12 in the figure may be operated manually, and although viroft pressure is used for convenience in opening and closing the communication valve 11, it can be replaced with an electric signal. is also easy.

Effects of the Invention In this invention, the swing braking performance of a hydraulic excavator can be easily improved from the driver's seat by using an automatic braking system using a hydraulic lock and a dynamic braking system that allows arbitrary braking force to be applied at any time as desired. It can be used selectively and also has a parking brake that maintains the turning position, so it can be used even in multi-process sites where various front attachments, cutting tools, etc. are replaced. It is economical because only one excavator is needed, and it is easy to operate.It also helps ensure safety by eliminating the need for tasks that previously required some driving skills.

[Brief explanation of drawings]

Figure 1 is an electric/hydraulic circuit diagram showing the brake system of the present invention, Figure 2 is a side view of a hydraulic excavator with a backhoe packet attached to the front attachment, Figure 3 is a side view of a hydraulic excavator equipped with a crane, and Figure 3 is a side view of a hydraulic excavator equipped with a crane. Figure 4 is an example of a hydraulic circuit diagram showing a swing operation system in a conventional hydraulic excavator; Figure 5 is an example of an electric/hydraulic circuit diagram in which a swing parking brake is added to the swing operation system of a conventional hydraulic excavator; This figure is an electric/hydraulic circuit diagram showing an improved modification of the embodiment shown in FIG. 5, and FIG. 7 is a hydraulic circuit diagram showing a swing system mainly used for cargo handling work. 6... Brake disc 11... Communication valve 12... Solenoid switching valve 13... Brake cylinder 17... Brake pedal 18... Master cylinder 32... Pressure switch 33... Timer or higher

Claims (1)

[Claims] In addition to the hydraulic lock type automatic swing brake valve consisting of a relief valve, check valve, etc. between the inflow and outflow oil passages for pressure oil for operating the swing motor, there is also a hydraulic lock type automatic swing brake valve that is installed between the oil passages that communicate the abovementioned outflow and inflow oil passages. The internal passage is open, and the communication valve closes when signal pressure is applied to the pilot oil chamber, and the outlet port normally receives pressure oil from a hydraulic source such as a pilot pump.
An electromagnetic switching valve that, when energized by a switch near the driver's seat, takes out the higher pressure of the pilot pressure oil that communicates with the two pilot oil chambers of the hydraulic switching valve for operating the swing motor, and switches the pressure oil from the shuttle valve to the outlet port. The outlet port of the electromagnetic switching valve and the pilot oil chamber of the communication valve are connected through an oil passage, and a brake disc on the output shaft of the swing motor is braked by a brake cylinder operated by a master cylinder linked to a brake pedal. What is claimed is: 1. A brake system for a revolving structure for a hydraulic excavator, characterized in that a dynamic brake device is provided, and a lock device is provided to mechanically hold the position of a brake pedal in a state in which the dynamic brake device is activated.