JPS6223330Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a hydraulic brake device for a training vehicle.

Generally, as shown in FIG. 1, a training course has a first master cylinder 2 operated by a brake pedal on the driver's seat (not shown) and a second master cylinder 4 operated by a brake pedal on the passenger seat (not shown). In a car, a common output for each brake system is communicated to switching valves 6 and 8 via brake pipes 2a, 4a and 2b, 4b, respectively, and only the master cylinder that is operated by the switching valves 6 and 8 is connected. The output is transmitted to the wheel cylinder.

Here, an example of a conventional switching valve will be described with reference to FIG. 2. The switching valve 6 has a cylinder 16 partitioned into two chambers 12 and 14 by a piston 10, and the chambers 12 and 14 are divided into two chambers 12 and 14, respectively. A passage 18 was formed in the inner wall of the cylinder 16 and communicated with the brake pipes 2a and 4a, and communicated with the wheel cylinder 22 through a brake pipe 20.

When the master cylinder 2 is in operation, the piston 10 moves to the right in FIG. When only the cylinder 4 is in operation, as the hydraulic pressure in the chamber 14 increases, the piston 10 moves to the left in FIG. Communication with the wheel cylinder 22 was always made through the passage 18.

However, for example, master cylinder 2 on the driver's side
If the master cylinder 2 is frequently used, the brake fluid in the chamber 14 is sent out to the pipe 4a every time the piston 10 moves to the right in FIG. There was a problem.

The present invention was devised in view of the above, and includes a first master cylinder operated by the brake pedal on the driver's seat side and a second master cylinder operated by the brake pedal on the passenger seat side. 3 by two pistons arranged
The cylinder includes a cylinder divided into two chambers, one end of which is in communication with the output hydraulic pressure chamber of the first master cylinder, and the other end of the three chambers is communicated with the output hydraulic pressure chamber of the second master cylinder. The central chamber communicates with the wheel cylinder and also communicates with the brake fluid reservoir via a check valve, and the two pistons are provided to be slidable within the respective cylinders, and the two pistons The first piston, which partitions the chamber at the one end from the central chamber, is urged toward the chamber at the one end by a biasing means, and the first piston is biased toward the chamber at the one end by a first stopper. The movement position of the second piston is restricted, and the second piston, which partitions the other end chamber from the center chamber, is urged toward the other end chamber by the urging means. The gist of the present invention is a hydraulic brake device for a training vehicle, characterized in that a second stopper restricts the maximum movement position of the other end toward the room.

According to the present invention, a brake fluid passage including the first master cylinder by the two pistons;
The brake fluid passage is completely divided into three brake fluid passages: the brake fluid passage containing the second master cylinder and the brake fluid passage containing the wheel cylinder, so even if only one of both master cylinders is used frequently, the brake fluid can only flow from one side to the other. The brake fluid is not discharged from one brake fluid passage to the other brake fluid passage, and the above-mentioned problems of the conventional device can be solved.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4. Note that in the drawings, parts that are substantially the same as those in the conventional device described above are designated by the same reference numerals as used above, and detailed explanations thereof will be omitted.

The switching valve 30 in this embodiment has two pistons 32 and 34 arranged in series.
The cylinder 42 is divided into two chambers 36, 38 and 40, and the chambers 36 and 40 at both ends are connected to the first master cylinder 2 by pipes 2a and 4a, respectively.
The central chamber 38 is connected to the wheel cylinder 22 through a pipe 20 and connected to the brake fluid reservoir 4 through a check valve 44.
It is connected to 6. A spring 48 as a biasing means compressed between the pistons 32 and 34 moves the pistons 32 and 34 to plugs 50 and 52 forming both end walls of the cylinder 42 and having communication ports 49 and 51 to the passages 2a and 4a. It is biased so that it comes into contact with. Furthermore, the piston 32
and 34 are provided with stopper portions 32a and 34a, respectively, and the maximum movement position of the piston 32 toward the chamber 36 is regulated by the stopper portion 32a coming into contact with the plug 50.
4, the maximum movement position toward the chamber 40 is regulated by the stopper portion 34a coming into contact with the plug 52. Air bleed members 54 and 56, such as air bleeders, are provided on the upper walls of the chambers 36 and 40, respectively.
is for discharging air accumulated in the chambers 36 and 40. When only the first master cylinder 2 is operating, the piston 32 moves to the right in FIG. 4
4 closes, hydraulic pressure is transmitted to the wheel cylinder 22, and the wheel cylinder 22 is operated. Furthermore, when only the second master cylinder 4 is operating, the piston 34
moves to the left in FIG. 4, the hydraulic pressure in the chamber 38 is increased, the check valve 44 is closed, and at the same time the hydraulic pressure is transmitted to the wheel cylinder 22 and the wheel cylinder 22 is operated. Furthermore, when both master cylinders 2 and 4 are operating, both chambers 36 and 40
As the hydraulic pressure increases, both pistons 32 and 34 move toward the center in FIG. 4, increasing the hydraulic pressure in the chamber 38, and the wheel cylinder 22 is similarly operated. In this case, of course, if there is a difference in the hydraulic pressure between the chambers 36 and 40, only one of the pistons 32 and 34 will move and the other will not.

In this way, according to the above configuration, the two pistons 32 and 34 connect three of the brake fluid passage including the first master cylinder 2, the brake fluid passage including the second master cylinder 4, and the brake fluid passage including the wheel cylinder 22. Since the brake fluid passages are completely divided into two brake fluid passages, even if only one of both master cylinders 2 and 4 is used frequently, brake fluid will not be sent from one brake fluid passage to the other brake fluid passage. This has the effect of eliminating the problems of the conventional device described above.

Next, a modification of the above embodiment will be explained in detail with reference to FIG. In the drawings, parts that are substantially the same as those shown in FIGS. 3 and 4 are designated by the same reference numerals as used above, and detailed explanations thereof will be omitted.

In this modification, the switching valve 30 has a cylinder 42 whose both end walls are constituted by plugs 60 and 62, and communication ports 64 and 66 between the chambers 36 and 40 and the passages 2a and 4a, respectively.
is formed on the upper wall of the Further, the chamber 38 is communicated via a check valve 44 and a pipe 67 with a brake fluid reservoir 68 which is appropriately supported on the vehicle body at a position apart from the cylinder 42.

According to the above configuration, it is possible to obtain the same effects as in the above embodiment, and also to connect the communication ports 64 and 66 between the chambers 36 and 40 and the pipes 2a and 4a.
are formed on the upper walls of the chambers 36 and 40, respectively, so that air can be prevented from accumulating in the chambers 36 and 40, thereby eliminating the need for air bleed members 54 and 56 as shown in FIG. be able to. Furthermore, since the reservoir 68 communicating with the chamber 38 is located apart from the cylinder 42, this is very advantageous when the space in which the cylinder 42 is installed is small.

In both of the above embodiments, the reservoir 46 or 68 can also be used in common with the reservoir in the master cylinder 2 or 4, and can also be used in common with the reservoir in the switching valve 32 in FIG. 3, which has the same structure as the switching valve 30. It is also possible.

[Brief explanation of the drawing]

Figure 1 is an overall view of the conventional device, and Figure 2 is the
3 is an overall view showing an embodiment of the present invention, FIG. 4 is a sectional view showing the switching valve 30 of FIG. 3, and FIG. 5 is a modification of the present invention. FIG. 2...First master cylinder, 4...Second master cylinder, 22...Wheel cylinder, 30,3
2...Switching valve, 32, 34...Piston, 3
6, 38, 40...Chamber, 42...Cylinder, 44
...Check valve, 46, 68...Reservoir.

Claims (1)

[Scope of utility model registration request] A cylinder having a first master cylinder operated by a brake pedal on the driver's seat side and a second master cylinder operated by a brake pedal on the passenger's seat side, in which two pistons arranged in series are used to control three chambers. comprising a compartmentalized cylinder;
The chamber at one end of the three chambers is communicated with the output hydraulic pressure chamber of the first master cylinder, the chamber at the other end is communicated with the output hydraulic pressure chamber of the second master cylinder, and the center chamber is connected to the wheel cylinder. The two pistons are provided to be slidable in the respective cylinders, and the one end chamber and the central chamber of the two pistons are connected to each other through a check valve. The partitioning first piston is urged toward the chamber side at the one end by the urging means, and the maximum movement position of the first piston toward the chamber side at the one end is restricted by the first stopper, so that the two pistons are A second piston that partitions the chamber at the other end from the center chamber is urged toward the chamber at the other end by a biasing means, and the second piston is urged toward the chamber at the other end by a second stopper. A hydraulic brake device for a training vehicle, characterized in that a maximum movement position is regulated.