JPH0321330Y2 - - Google Patents

Description

[Detailed explanation of the idea] <Industrial application field> The present invention relates to a power steering device.

<Prior art> A power steering device is a steering system equipped with a booster to reduce steering force, and a hydraulic type is a steering system in which oil is sent from an oil pump driven by an engine. It's summery.

A conventional example of such a power steering device is shown in FIG.

This one is a rack and pinion type,
A rotary valve 2 as a control valve is provided on one shaft of the pinion, a power cylinder 4 is provided on the third shaft of the rack, and the rotary valve 2 and the power cylinder 4 are connected by a pipe 5 or the like.

The rotary valve 2 is connected to the steering wheel 6
It is composed of a rotor (not shown) connected to an input shaft to which steering force is transmitted, and a sleeve connected to an output shaft, and the rotor provides a valve function by rotating relative to the sleeve. There is.

The oil sent from the oil pump 7 is controlled according to the function of the rotary valve 2 which is activated by the driver's steering, and the amount of oil is adjusted according to the right or left operating direction, the operating speed, and the steering load. A corresponding hydraulic pressure is determined and guided to a power cylinder 4 as an actuator, thereby boosting the steering output.

<Problems to be solved by the invention> However, in such a conventional hydraulic power steering device, since the engine-driven oil pump 7 is not rotating, there is a large energy loss, and the engine It also affected fuel efficiency.

The present invention was devised in view of these conventional problems, and provides a power steering device that uses the vacuum pressure in the intake passage as the power assist source, thereby eliminating the need to extract excess power from the engine. The purpose is to provide

<Means for Solving the Problems> For this reason, the present invention provides a vacuum cylinder having two chambers defined by a piston, a passage for extracting vacuum pressure from the suction passage of the engine, and a vacuum cylinder with the piston placed in a neutral position or one side. a control valve that controls the opening and closing of a passage that guides vacuum pressure from the passage to two chambers and a passage that opens the two chambers to the atmosphere in response to a steering input, respectively, so as to operate the vacuum chamber to the position moved to the vacuum chamber; and means for transmitting the steering output boosted by the cylinder to the steering link.

<Operation> Then, according to the function of the control valve activated by the driver's steering, the state of action of the vacuum pressure on the vacuum cylinder is controlled, and the vacuum cylinder boosts the steering output by the vacuum pressure. It is operated as follows. This steering output is transmitted to the steering link.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5.

In FIG. 1, 10 is a vacuum cylinder having two chambers 12 and 13 defined by a piston 11, each of which has a port 12 and 13.
a, 13a are provided. The shaft portion 11a of the piston 11 of this vacuum cylinder 10 is connected to the shaft portion of the rack 14.

On the other hand, one end of a pipe 15 serving as a passage for taking out the vacuum pressure in the intake passage of the engine is connected directly downstream of the throttle valve 17 of the intake manifold 16, and the other end of the pipe 15 is connected via a check valve 18 and a surge tank 19. It is connected to a supply port 21 of a rotary valve 20 as a control valve to be described later. The rotary valve 20 is configured as shown in FIGS.
The rotor 23 has a rotor 23 connected to an input shaft 22 to which the steering force from the rotor 23 is transmitted, and a sleeve 26 connected to an output shaft 24 connected to the shaft of a pinion 25 that meshes with the rack 14. The valve function is provided by rotation relative to the sleeve 26.

In the rotary valve 20, 27 is the pipe 2
8 is a port connected to one port 12a of the vacuum cylinder 10, 42 is a port connected to the other port 13a via a pipe 29, and 30 is a port open to the atmosphere. Then, the piston 1 is connected by pipes 28 and 29.
A passage is configured to guide the vacuum pressure from the pipe 15 to the two chambers 12 and 13 so that the port 30 is moved to a neutral position or a position moved to one side.
This forms a passage that opens the two chambers 12 and 13 to the atmosphere.

The means for transmitting the steering output boosted by the vacuum cylinder 10 to the steering link as shown in FIG. 6 is the shaft portion 11a of the piston 11.
and the rack 14 shaft portion are connected to the steering link.

Next, the operation of this configuration will be explained.

Figure 3 shows the rotary valve 20 in the neutral state.
Vacuum pressure from pipe 15 acts on supply port 21, but no output is produced since supply port 21 communicates with port 30, which is open to the atmosphere.

FIG. 4 shows a state in which the rotor 23 of the rotary valve 20 is rotating relative to the sleeve 26 due to the steering input when steering to the right, and the vacuum pressure from the pipe 15 is pumped from the port 27 through the pipe 28 and the port 12a. It acts on the chamber 12 of the Yum cylinder 10 and moves the piston 11. Air is drawn into the other chambers 13 through ports 30 that are open to the atmosphere.
This moves the steering link. The movement of the steering link is transmitted to the sleeve 26 that is integrated with the steering link, and while the steering input is applied, the rotor 23 and the sleeve 26 rotate while maintaining a relative displacement, but when the steering input is stopped, the sleeve 26 moves to the rotor 23. It moves so as to cancel out the relative displacement between the two and returns to the state shown in FIG.

FIG. 5 shows another embodiment of the means for transmitting the steering output boosted by the vacuum cylinder 50 to the steering link, which includes a piston 32 connected to the shaft portion 31a of the piston 31 of the vacuum cylinder 50. A hydraulic cylinder 35 is provided having two chambers 33, 34 defined by the piston 32. On the other hand, a hydraulic cylinder 39 having two chambers 37 and 38 defined by a piston 36
is provided. The shaft portion 36a of the piston 36 of this hydraulic cylinder 39 is connected to the shaft portion of the rack 14.

And the chambers 33 and 34 of the hydraulic cylinder 35,
The chambers 37 and 38 of the hydraulic cylinder 39 are connected through pipes 40 and 41 provided therein. Therefore, in this embodiment, the vacuum cylinder 5
The steering output boosted by 0 is converted into hydraulic pressure and transmitted to the steering link.

In this case, in conjunction with the operation of the piston 31 of the vacuum cylinder 50, the hydraulic cylinders 35 and 39
Oil is circulated between the hydraulic cylinder 39 and the piston 36 of the hydraulic cylinder 39 by the movement of the oil.

According to this configuration, by using the vacuum pressure in the intake passage of the engine as the power assist source, it is possible to create a configuration in which excess power is not extracted from the engine, and it is possible to create a configuration in which the oil pump driven by the engine is not rotated. Unlike the previous model, the energy loss is not large, and it is possible to improve the fuel efficiency of the engine.

In addition, in such a configuration, the vacuum pressure increases as the engine speeds lower, and the vacuum pressure decreases as the engine speeds higher.As a result, the steering feeling at high speeds is improved, etc., resulting in an engine speed sensitive device. You can also.

<Effects of the invention> As explained above, according to the invention, by using the vacuum pressure of the intake passage of the engine as the power assist source, it is possible to create a configuration in which no excess power is extracted from the engine. This has great practical effects, such as reducing energy loss and making it possible to improve engine fuel efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of a power steering device according to the present invention, FIG. 2 is a sectional view showing the structure of a rotary valve in the same device, and FIG.
4 and 4 are sectional views showing the structure of the valve portion of the rotary valve described above, FIG. 5 is a schematic view showing another embodiment, and FIG. 6 is a schematic view of a conventional example. 10,50... Vacuum cylinder, 11,3
1... Piston, 12, 13... Chamber, 15... Pipe, 16... Intake manifold, 20...
Rotary valve, 35, 39...hydraulic cylinder.

Claims (1)

[Scope of utility model registration request] a vacuum cylinder having two chambers defined by a piston; a passage for extracting vacuum pressure from an engine suction passage; and a vacuum cylinder from said passage for operating said piston to a neutral position or a shifted position. A control valve that controls the opening and closing of a passage that leads pressure to the two chambers and a passage that opens the two chambers to the atmosphere in response to steering input, and transmits the steering output boosted by the vacuum cylinder to the steering link. A power steering device characterized by comprising means.