WO2023184829A1

WO2023184829A1 - Parking brake hydraulic control system and forklift loader

Info

Publication number: WO2023184829A1
Application number: PCT/CN2022/113233
Authority: WO
Inventors: 刘国良; 魏星; 孙荣武; 赵俊波; 陈学良
Original assignee: 湖南星邦智能装备股份有限公司
Priority date: 2022-04-01
Filing date: 2022-08-18
Publication date: 2023-10-05
Also published as: CN114593166A

Abstract

A parking brake hydraulic control system and a forklift loader. The parking brake hydraulic control system is applied to a vehicle and comprises: a parking brake (1), which comprises an oil port P1; a parking brake hydraulic oil path connected to the oil port P1 and used for supplying hydraulic oil to the parking brake (1) or releasing pressure of the parking brake (1); a first electromagnetic reversing valve (2) provided on the parking brake hydraulic oil path and used for switching the oil flow direction of the parking brake hydraulic oil path; and a flow control valve (3) provided on the parking brake hydraulic oil path, located between the first electromagnetic reversing valve (2) and the parking brake (1), and used for adjusting the pressure relief flow of the parking brake (1) when the vehicle is suddenly stopped.

Description

Parking brake hydraulic control system and forklift

This application requires the priority of the Chinese patent application submitted to the China Patent Office on April 1, 2022, with the application number 202210339530.3 and the invention name "A Parking Brake Hydraulic Control System and a Forklift Truck". All its contents have been approved. This reference is incorporated into this application.

Technical field

The present invention relates to the technical field of parking brake control, and more specifically, to a parking brake hydraulic control system. In addition, the present invention also relates to a forklift including the above-mentioned parking brake hydraulic control system.

Background technique

When a vehicle such as a high-level forklift is traveling and encounters an emergency, the driver will press the emergency stop button to shut down the vehicle engine. At this time, all hydraulic pumps will stop supplying oil, which causes the vehicle parking device to When driving at high speed, the vehicle quickly resets and locks up, resulting in a large impact or even rollover of the vehicle, posing a major safety hazard.

In the prior art, in order to avoid a large impact or rollover of the vehicle during emergency braking, a one-way valve is added in front of the oil inlet line of the electromagnetic reversing valve of the parking brake hydraulic circuit. In this way, when the hydraulic pressure After the pump stops supplying oil, the one-way valve can be used to maintain pressure for a period of time. After the vehicle slows down, the electromagnetic reversing valve is switched to release the parking brake pressure and then reset the brake.

However, by adding a one-way valve in front of the oil inlet line of the electromagnetic reversing valve, although the electromagnetic reversing valve can be delayed to switch, a certain parking pressure can be effectively maintained to avoid directly pressing the parking brake after emergency stop. In the case of locking, however, it is still difficult to avoid vehicle impact at the moment of pressure relief after the electromagnetic reversing valve is switched.

To sum up, how to avoid impact during emergency braking of the vehicle and at the moment of pressure release is an urgent problem that needs to be solved by those skilled in the art.

Contents of the invention

In view of this, the object of the present invention is to provide a parking brake hydraulic control system that can avoid impacts during emergency braking of the vehicle and at the moment of pressure release.

Another object of the present invention is to provide a forklift including the above-mentioned parking brake hydraulic control system, which can ensure smooth parking during emergency stop and avoid vehicle impact.

In order to achieve the above objects, the present invention provides the following technical solutions:

A parking brake hydraulic control system, applied to vehicles, including:

Parking brake, which includes oil port P1;

The parking brake hydraulic oil circuit is connected to the oil port P1 and is used to supply hydraulic oil to the parking brake or relieve the pressure of the parking brake;

A first electromagnetic reversing valve is provided in the parking brake hydraulic oil circuit and is used to switch the oil flow direction of the parking brake hydraulic oil circuit;

A flow control valve is provided in the parking brake hydraulic oil circuit and is located between the first electromagnetic reversing valve and the parking brake, used to adjust the parking brake when the vehicle makes an emergency stop. pressure relief flow.

Optionally, a second electromagnetic reversing valve is also included, which is arranged in parallel with the flow control valve. The second electromagnetic reversing valve is in a normally open mode, and the flow control valve is in a normally closed mode.

Optionally, a pressure sensor for real-time monitoring of the pressure of the oil port P1 is also included.

Optionally, the pressure sensor is connected to a controller, the controller is also connected to the flow control valve and a rotational speed sensor, the rotational speed sensor is used to detect the walking speed of the vehicle, and the controller is used to detect when the vehicle is moving. When the vehicle makes an emergency stop, the opening of the flow control valve is controlled and adjusted according to the traveling speed of the vehicle and the pressure of the oil port P1.

Optionally, when the vehicle makes an emergency stop, when the first electromagnetic reversing valve switches working positions and the second electromagnetic reversing valve is closed, the controller controls and adjusts the flow control after delaying a preset time. The opening of the valve.

Optionally, the flow control valve includes an electrically proportional flow valve or a servo valve.

Optionally, the first electromagnetic reversing valve includes a switching valve, a proportional valve or a servo valve; and/or the second electromagnetic reversing valve includes a switching valve, a proportional valve or a servo valve.

Optionally, the parking brake hydraulic oil circuit includes:

A hydraulic pump used to provide a source of hydraulic power to which a prime mover is connected;

The oil inlet path has one end connected to the outlet of the hydraulic pump and the other end connected to the oil inlet P of the first electromagnetic reversing valve;

The oil return path has one end connected to the hydraulic oil tank and the other end connected to the oil return port T of the first electromagnetic reversing valve;

The connecting oil line is connected between the working oil port A of the first electromagnetic reversing valve and the oil port P1, and the flow control valve is provided in the connecting oil line.

Optionally, a relief valve is connected between the outlet of the hydraulic pump and the hydraulic oil tank.

A forklift includes any one of the above parking brake hydraulic control systems.

The parking brake hydraulic control system provided by the present invention can control and adjust the flow rate before the first electromagnetic reversing valve switches positions when the driver slaps an emergency stop to stall the vehicle engine during normal driving of the vehicle. Control the opening of the valve so that the flow control valve has an appropriate flow rate, and then switch the first electromagnetic reversing valve so that the parking brake hydraulic oil circuit is used to release pressure from the parking brake. At this time, the parking brake can be Slow pressure relief and reset prevents the parking brake from locking directly after an emergency stop, achieving smooth parking and avoiding vehicle impact. That is, even at the moment of pressure relief after the first electromagnetic reversing valve is switched, Can avoid vehicle impact. It can be seen that the parking brake hydraulic control system can avoid the impact of the vehicle during emergency braking, and there will be no impact at the moment of pressure release.

The forklift provided by the present invention includes the above-mentioned parking brake hydraulic control system, which has the above-mentioned beneficial effects and can ensure smooth parking during emergency stop and avoid vehicle impact.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

Figure 1 is a control principle diagram of a parking brake hydraulic control system provided by a specific embodiment of the present invention.

The reference numbers in Figure 1 are as follows:

1 is the parking brake, 2 is the first electromagnetic reversing valve, 3 is the flow control valve, 4 is the second electromagnetic reversing valve, 5 is the pressure sensor, 6 is the hydraulic pump, 7 is the prime mover, and 8 is the oil inlet. , 9 is the return oil line, 10 is the hydraulic oil tank, 11 is the connecting oil line, 12 is the relief valve, and 13 is the preset drive oil line.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The core of the present invention is to provide a parking brake hydraulic control system that can avoid impact during emergency braking of the vehicle and at the moment of pressure release. Another core of the present invention is to provide a forklift including the above-mentioned parking brake hydraulic control system, which can ensure smooth parking during emergency stop and avoid vehicle impact.

Please refer to Figure 1, which is a control principle diagram of the parking brake hydraulic control system provided by a specific embodiment of the present invention.

Embodiments of the present invention provide a parking brake hydraulic control system for use in vehicles. The parking brake hydraulic control system includes a parking brake 1, a parking brake hydraulic oil circuit, a first electromagnetic reversing valve 2 and a flow rate. Control valve 3, the parking brake 1 includes an oil port P1; the parking brake hydraulic oil circuit is connected to the oil port P1, and is used to supply hydraulic oil to the parking brake 1, or to relieve the pressure of the parking brake 1; the first electromagnetic switch Directional valve 2 is located in the parking brake hydraulic oil circuit and is used to switch the oil flow direction of the parking brake hydraulic oil circuit; flow control valve 3 is located in the parking brake hydraulic oil circuit and is located in the first electromagnetic reversing valve. 2 and parking brake 1, used to adjust the pressure relief flow of parking brake 1 when the vehicle makes an emergency stop.

It can be understood that when the vehicle is running normally, the hydraulic oil in the parking brake hydraulic oil circuit supplies hydraulic oil to the oil port P1 of the parking brake 1 through the first electromagnetic reversing valve 2 and the flow control valve 3. Under the action of oil, the parking brake 1 is in an unlocked state to meet the normal driving requirements of the vehicle. It should be noted that under this working condition, the flow control valve 3 can be controlled to be at the maximum flow, so that the hydraulic oil supplied by the parking brake hydraulic oil circuit can quickly flow into the oil port P1 of the parking brake 1 to ensure that the vehicle starts Quick release of parking brake 1 while walking.

During the normal running of the vehicle, when the driver slaps the emergency stop to stall the vehicle engine, the flow control valve 3 can be controlled to adjust the opening of the flow control valve 3 before the first electromagnetic reversing valve 2 switches working positions. Valve 3 has an appropriate flow rate, and then switches the first electromagnetic reversing valve 2 so that the parking brake hydraulic oil circuit is used to relieve pressure on parking brake 1. At this time, parking brake 1 can be slowly relieved and reset to prevent After the emergency stop, the parking brake 1 is directly locked to achieve smooth parking and avoid the vehicle impact. That is, even at the moment of pressure relief after the first electromagnetic reversing valve 2 is switched, the vehicle can be prevented from occurring. impact. It can be seen that the parking brake hydraulic control system can avoid the impact of the vehicle during emergency braking, and there will be no impact at the moment of pressure release.

In addition, it can be understood that during the normal driving process of the vehicle, when the vehicle stops normally, the first electromagnetic reversing valve 2 switches the position, so that the hydraulic oil in the parking brake 1 is discharged through the parking brake hydraulic oil circuit. Press, at this time, under the action of the spring of parking brake 1, the parking brake function is realized. It should be noted that under this working condition, the flow control valve 3 can be controlled to be at the maximum flow, so that the hydraulic oil in the parking brake 1 can quickly release pressure and achieve rapid parking braking during normal parking.

It should be noted that in order to enable the parking brake 1 to quickly unlock when the vehicle first starts to move and to implement the rapid parking brake during normal parking, it is necessary to ensure that the flow control valve 3 has a large enough flow capacity when it is at the maximum flow rate.

Further, in order to facilitate control, in some embodiments, a second electromagnetic reversing valve 4 is also included. The second electromagnetic reversing valve 4 is arranged in parallel with the flow control valve 3. The second electromagnetic reversing valve 4 is in a normally open mode. Flow control valve 3 is in normally closed mode.

It is understandable that normal walking and normal parking of vehicles are the norm, while the number of emergency stops of vehicles is relatively rare. Therefore, this embodiment adds a second electromagnetic reversing valve 4 and sets the second electromagnetic reversing valve 4 to a normally open mode and the flow control valve 3 to a normally closed mode, so that when the vehicle is running normally and parking normally, the first electromagnetic reversing valve 4 is normally opened and the flow control valve 3 is normally closed. The oil path between the reversing valve 2 and the oil port P1 is connected through the second electromagnetic reversing valve 4. That is, whether the vehicle is running normally or the vehicle is parking normally, the second electromagnetic reversing valve 4 is connected. The valves 4 are all in the open state, the flow control valve 3 is in the closed state, and the flow control valve 3 does not work. In this way, it is possible to avoid adjusting the flow control valve 3 when the vehicle is running normally and parking normally, and it is convenient to control; at the same time, the flow control valve 3 can be adjusted Achieve quick unlocking and quick parking brake of parking brake 1 to meet the normal use needs of the vehicle. When the driver slaps the emergency stop, the second electromagnetic reversing valve 4 is closed, the flow control valve 3 is opened, and the oil path between the first electromagnetic reversing valve 2 and the oil port P1 is connected through the flow control valve 3 to ensure that the current When the vehicle makes an emergency stop, the pressure relief flow of the parking brake 1 is adjusted by adjusting the opening of the flow control valve 3, so that the oil port P1 of the parking brake 1 slowly releases pressure to achieve smooth parking during an emergency stop.

Specifically, when the vehicle is running normally, the first electromagnetic reversing valve 2 is open, the second electromagnetic reversing valve 4 is in an open state, and the hydraulic oil in the parking brake hydraulic oil circuit passes through the first electromagnetic reversing valve 2 and the second electromagnetic reversing valve 4. The two electromagnetic reversing valves 4 supply hydraulic oil to the oil port P1 of the parking brake 1. Under the action of the hydraulic oil, the parking brake 1 is in an unlocked state to meet the normal driving requirements of the vehicle.

When the vehicle stops normally, the first electromagnetic reversing valve 2 switches positions, and the second electromagnetic reversing valve 4 continues to remain open. After the hydraulic oil in the parking brake 1 flows out from the oil port P1, it passes through the parking brake hydraulic pressure. The oil circuit performs pressure relief. During the pressure relief process, the hydraulic oil passes through the second electromagnetic reversing valve 4 and the first electromagnetic reversing valve 2 in sequence. At this time, under the action of the spring of the parking brake 1, the parking brake is realized. Function.

When the driver slaps the emergency stop to stall the vehicle engine, the first electromagnetic reversing valve 2 switches to the working position, and the second electromagnetic reversing valve 4 is closed. At this time, since the flow control valve 3 is in a closed state, the vehicle can be parked. The oil port P1 of brake 1 maintains pressure to prevent parking brake 1 from directly locking up when the vehicle is at high speed. Then, the opening of the flow control valve 3 can be adjusted by controlling the flow control valve 3 so that the flow control valve 3 has an appropriate flow rate, so that the oil port P1 of the parking brake 1 can slowly release the pressure to achieve smooth parking during emergency stops. , to avoid vehicle impact and rollover.

In addition, in order to be able to monitor the pressure of the oil port P1 of the parking brake 1 in real time, in some embodiments, the parking brake hydraulic control system also includes a pressure sensor 5 for real-time monitoring of the pressure of the oil port P1. That is, this embodiment adds a pressure sensor 5 to monitor the pressure of the oil port P1 of the parking brake 1 in real time, so as to adjust the opening of the flow control valve 3 according to the pressure of the oil port P1 of the parking brake 1 .

Further, in some embodiments, the pressure sensor 5 is connected to a controller, and the controller is also connected to the flow control valve 3 and a rotational speed sensor. The rotational speed sensor is used to detect the walking speed of the vehicle, and the controller is used to detect the vehicle's walking speed when the vehicle suddenly stops. The traveling speed of the vehicle and the pressure of the oil port P1 control and adjust the opening of the flow control valve 3.

When working, the pressure sensor 5 collects and monitors the pressure of the oil port P1 of the parking brake 1, and sends the pressure of the oil port P1 of the parking brake 1 to the controller; the rotation speed sensor collects and monitors the walking speed of the vehicle, and sends the pressure of the oil port P1 of the parking brake 1 to the controller. The walking speed is sent to the controller; after the controller receives the pressure of the oil port P1 and the walking speed of the vehicle, it sends a control signal to the flow control valve 3 according to the pressure of the oil port P1 and the walking speed of the vehicle to control the real-time adjustment of the flow control. The opening of valve 3 allows the oil port P1 of parking brake 1 to slowly release pressure, achieving smooth parking during emergency stops at different vehicle speeds.

Further, in some embodiments, when the vehicle makes an emergency stop, after the first electromagnetic reversing valve 2 switches working positions and the second electromagnetic reversing valve 4 is closed, the controller controls and adjusts the flow control valve 3 after delaying a preset time. Opening size. That is to say, when the first electromagnetic reversing valve 2 switches working positions and the second electromagnetic reversing valve 4 is closed, at this time, the flow control valve 3 is in a normally closed state, and the parking brake hydraulic control system maintains pressure for a preset time. To prevent the parking brake 1 from directly locking up when the vehicle is at high speed; after the parking brake hydraulic control system maintains pressure for a preset time, the controller then controls the flow control valve 3 to open a certain opening, so that the parking brake 1 The oil port P1 slowly releases pressure to achieve smooth parking and avoid vehicle impact and rollover.

It should be noted that this embodiment does not specifically limit the value of the delayed preset time. In some embodiments, the preset time is 1 to 5 seconds, that is, when the first electromagnetic reversing valve 2 switches position and the second electromagnetic reversing valve 4 is closed, the controller delays for 1 to 5 seconds before controlling and adjusting the opening of the flow control valve 3.

It should be noted that in each of the above embodiments, the type of the flow control valve 3 is not specifically limited, as long as it can realize flow adjustment.

In some embodiments, the flow control valve 3 includes an electrically proportional flow valve or a servo valve.

In addition, in the above-mentioned embodiments, the types of the first electromagnetic reversing valve 2 and/or the second electromagnetic reversing valve 4 are not specifically limited, as long as the first electromagnetic reversing valve 2 and the second electromagnetic reversing valve can be realized. The corresponding functions of the valves 4 are enough.

In some embodiments, the first electromagnetic reversing valve 2 includes a switching valve, a proportional valve or a servo valve.

In some embodiments, the second solenoid directional valve 4 includes a switching valve, a proportional valve or a servo valve.

In addition, the first electromagnetic reversing valve 2 may be a two-position valve or a three-position valve; it may also be a three-way valve or a four-way valve. The second electromagnetic reversing valve 4 can be a two-position valve or a three-position valve.

It should be noted that the above embodiments do not limit the specific composition of the parking brake hydraulic oil circuit, as long as the parking brake hydraulic oil circuit can provide hydraulic oil with stable pressure and can return oil.

In some embodiments, the parking brake hydraulic oil circuit includes a hydraulic pump 6, a prime mover 7, an inlet oil circuit 8, a return oil circuit 9 and a connecting oil circuit 11. The hydraulic pump 6 is used to provide a hydraulic power source. The hydraulic pump 6 It is connected to the prime mover 7; one end of the oil inlet path 8 is connected to the outlet of the hydraulic pump 6, and the other end is connected to the oil inlet P of the first electromagnetic reversing valve 2; one end of the return oil path 9 is connected to the hydraulic oil tank 10, and the other end is connected to the hydraulic oil tank 10. One end is connected to the oil return port T of the first solenoid reversing valve 2; the connecting oil line 11 is connected between the working oil port A and the oil port P1 of the first solenoid reversing valve 2, and the flow control valve 3 is located in the connecting oil line 11.

It should be noted that this embodiment does not limit the type of the hydraulic pump 6. For example, the hydraulic pump 6 can be a fixed pump or a variable displacement pump.

In some embodiments, the outlet of the hydraulic pump 6 is also connected to a preset driving oil line 13, which is used to supply oil to the preset actuator. That is to say, the hydraulic pump 6 can not only supply hydraulic oil to the parking brake hydraulic oil circuit, but also supply hydraulic oil to other preset actuators.

In some embodiments, a relief valve 12 is connected between the outlet of the hydraulic pump 6 and the hydraulic oil tank 10 . The relief valve 12 can adjust the maximum pressure output by the hydraulic pump 6 to the parking brake hydraulic oil circuit to ensure the safety of the parking brake hydraulic control system.

In addition to the above parking brake hydraulic control system, the present invention also provides a forklift including the parking brake hydraulic control system disclosed in the above embodiment. Please refer to the prior art for the structure of other parts of the forklift. This article will not go into details.

It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations There is no such actual relationship or sequence between operations.

Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on its differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other.

The parking brake hydraulic control system and the forklift truck provided by the present invention have been introduced in detail above. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and the core idea of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of the claims of the present invention.

Claims

A parking brake hydraulic control system, applied to vehicles, is characterized by including:

Parking brake (1), which includes oil port P1;

The parking brake hydraulic oil circuit is connected to the oil port P1 and is used to supply hydraulic oil to the parking brake (1) or relieve the pressure of the parking brake (1);

The first electromagnetic reversing valve (2) is located in the parking brake hydraulic oil circuit and is used to switch the oil flow direction of the parking brake hydraulic oil circuit;

A flow control valve (3) is provided in the parking brake hydraulic oil circuit and is located between the first electromagnetic reversing valve (2) and the parking brake (1). It is used when the vehicle Adjust the pressure relief flow of the parking brake (1) during emergency stop.
The parking brake hydraulic control system of claim 1, further comprising a second electromagnetic reversing valve (4), which is arranged in parallel with the flow control valve (3), and the second electromagnetic reversing valve (4) is arranged in parallel with the flow control valve (3). The directional valve (4) is in a normally open mode, and the flow control valve (3) is in a normally closed mode.
The parking brake hydraulic control system according to claim 1 or 2, further comprising a pressure sensor (5) for real-time monitoring of the pressure of the oil port P1.
The parking brake hydraulic control system according to claim 3, characterized in that the pressure sensor (5) is connected to a controller, and the controller is also connected to the flow control valve (3) and the rotation speed sensor, The rotation speed sensor is used to detect the walking speed of the vehicle, and the controller is used to control and adjust the flow control valve according to the walking speed of the vehicle and the pressure of the oil port P1 when the vehicle makes an emergency stop. (3) The opening size.
The parking brake hydraulic control system according to claim 4, characterized in that when the vehicle makes an emergency stop, when the first electromagnetic reversing valve (2) switches working positions and the second electromagnetic reversing valve (4) After closing, the controller controls and adjusts the opening of the flow control valve (3) after delaying a preset time.
The parking brake hydraulic control system according to claim 1 or 2, characterized in that the flow control valve (3) includes an electrical proportional flow valve or a servo valve.
The parking brake hydraulic control system according to claim 2, characterized in that the first electromagnetic reversing valve (2) includes a switching valve, a proportional valve or a servo valve; and/or the second electromagnetic reversing valve (2) Directional valves (4) include on-off valves, proportional valves or servo valves.
The parking brake hydraulic control system according to claim 1 or 2, characterized in that the parking brake hydraulic oil circuit includes:

A hydraulic pump (6) used to provide a hydraulic power source, which is connected to a prime mover (7);

The oil inlet passage (8) has one end connected to the outlet of the hydraulic pump (6) and the other end connected to the oil inlet P of the first electromagnetic reversing valve (2);

The oil return path (9) has one end connected to the hydraulic oil tank (10) and the other end connected to the oil return port T of the first electromagnetic reversing valve (2);

The connecting oil line (11) is connected between the working oil port A of the first electromagnetic reversing valve (2) and the oil port P1, and the flow control valve (3) is located in the connecting oil line ( 11).
The parking brake hydraulic control system according to claim 8, characterized in that a relief valve (12) is connected between the outlet of the hydraulic pump (6) and the hydraulic oil tank (10).
A forklift, characterized by including the parking brake hydraulic control system according to any one of claims 1-9.