JPH0430352Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an atmosphere intake structure for an exhaust brake switching valve in a vehicle having an exhaust brake.

[Technical background of the invention and its problems] An exhaust brake valve consisting of a butterfly valve is installed in the middle of the engine exhaust pipe, and by closing this exhaust brake valve during the exhaust process, the air pressure in the exhaust manifold is compressed. Vehicles equipped with an exhaust brake that provide braking force are provided with a switching valve, such as a three-way magnetic valve, that operates the actuator of the exhaust brake valve.

This three-way magnetic valve has a first port that connects to the vacuum tank, a second port that connects to the actuator of the exhaust brake valve, and a third port that communicates with the atmosphere. The first and second ports are in communication, and the second and third ports can be electrically switched to communicate when they are off.

By the way, the atmospheric air intake port of the conventional three-way magnetic valve is provided on the clean side of the air cleaner or in the vicinity of the three-way magnetic valve, and a small air filter is attached to take in the atmospheric air. However, when air is taken in from the air cleaner, a dedicated nipple is required for the air cleaner, and piping must be routed to the three-way magnetic valve, which increases costs. In addition, when the three-way magnetic valve is installed in the vicinity of the atmosphere, the small air filter becomes clogged with muddy water and dust, causing the inconvenience of losing the ability to take in the atmosphere.

[Purpose of the invention] This invention was made with attention to the above-mentioned circumstances, and its purpose is to eliminate the need for air intake piping for the 3-way magnetic valve that serves as the exhaust brake switching valve, and to improve the layout. It is an object of the present invention to provide an atmosphere intake structure for an exhaust brake switching valve that is advantageous for the use of an exhaust brake and can prevent muddy water from entering without providing an air filter.

[Summary of the invention] In order to achieve the above-mentioned object, this invention provides an air intake port for the exhaust brake switching valve to one hollow leg of a portal-shaped hollow rear cab mount pipe installed in the vehicle. A cap is provided at the lower end of one of the hollow legs to prevent muddy water from entering.
It is characterized in that an air intake port is formed at the lower end of the other hollow leg.

[Embodiment of the invention] An embodiment of the invention will be described below based on the drawings.

In FIGS. 1 and 2, 1 indicates a vehicle such as a truck, 2 a chassis frame, and 3 a cab. This cab 3 is the front cab 4
is connected to the chassis frame 2 by the tilt hinge 5.
The rear cab 6 is supported by a rear cab mount pipe 7 (hereinafter simply referred to as mount pipe). This mount pipe 7 is formed by bending a hollow pipe into a gate shape. That is, it has left and right hollow leg portions 7a, 7a extending upwardly of the chassis frame 2, and a hollow beam portion 7b communicating these hollow leg portions 7a, 7a. The lower ends of the hollow legs 7a, 7a are fixed to the chassis frame 2 by brackets 8, 8, and both ends of the hollow legs 7a, 7a of the mount pipe 7 are open. moreover,
Support members 10, 10 are provided on the hollow legs 7a, 7a of the mount pipe 7 via brackets 9, 9, and the rear cab 6 is supported by these support members 10, 10. The chassis frames 2, 2 located at the bottom of the cab 3
An engine 11 is mounted between them.

As shown in FIG. 3, the engine 11 is provided with an exhaust pipe 13 connected to an exhaust manifold 12, and an exhaust brake valve 14 is provided in the middle of the exhaust pipe 13. This exhaust brake valve 1
4 is composed of a butterfly valve 15 and an actuator 16 for opening and closing the valve 15, as is well known. This actuator 16 is operated by a three-way magnetic valve 17 as a switching valve, which will be described later. As shown in FIG. 4, this three-way magnetic valve 17 has a mounting plate 18 attached to a bracket 9 provided in the hollow leg portion 7a of the mount pipe 7.
The three-way magnetic valve 17 has a first port 21, a second port 22, and a third port 23, and when turned on by an electric signal, the three-way magnetic valve 17 The first and second ports 21 and 22 communicate with each other, and the second and third ports 22 and 23 communicate with each other when the switch is off. and the 3-way magnetic valve 1
The second port 22 of No. 7 is connected to the actuator 16 via piping 24, and the first port 21
is connected to a vacuum tank 25 mounted on the vehicle 1 via a pipe 26. Furthermore, the third port 23 passes through a through hole 27 provided in the side wall of one hollow leg 7a of the mount pipe 7 located nearby and opens into a hollow part 28 in the pipe, allowing atmospheric intake. A portion 29a is formed. That is, the hollow legs 7a, 7a of the mount pipe 7 are open at both ends, and are in communication with the atmosphere. A cap 30 for preventing muddy water from entering is attached to the lower end of one hollow leg 7a, that is, one hollow leg 7a to which the third port 23 is connected, and the lower end of the other hollow leg is opened and exposed to the atmosphere. The intake port is 29. Incidentally, the cap 30 may be provided with a small exhaust hole in case of muddy water. In addition, 31 is engine 1
1, which is connected to a pipe 26 connecting the first port 21 and the vacuum tank 25 via a pipe 32.

According to the atmosphere intake structure of the 3-way magnetic valve as the exhaust brake switching valve configured in this way, by turning on the 3-way magnetic valve 17, the first port 21 and the second port 22 are switched on. is in communication state, and the actuator 16
When activated, the butterfly valve 15 can be rotated to apply the exhaust brake, and when turned off, the second port 22 and the third port 23 communicate with each other.
Actuator 16 can communicate with the atmosphere to release the exhaust brake. At this time, since the third port 23 of the three-way magnetic valve 17 opens into the hollow leg portion 7a of the mount pipe 7, there is no fear of muddy water or dust entering.

[Effects of the invention] As explained above, according to this invention, the hollow rear cab mount pipe is formed into a gate shape with left and right hollow legs and a hollow beam, and one hollow leg A cap is attached to the lower end to prevent muddy water from entering, and the lower end of the other hollow leg is opened to serve as an air intake, and the third port of the exhaust brake switching valve is installed in the middle of the one hollow leg. When the exhaust brake is activated, the air in the rear cab mount pipe is introduced into the exhaust brake switching valve, and the cap prevents muddy water from entering around the third port of the exhaust brake switching valve. can be prevented from scattering.

In addition, the third port of the exhaust brake switching valve is
Since it is provided in the middle of one of the hollow legs on the opposite side to the other hollow leg which has the atmospheric air intake at the lower end, the path through which the exhaust brake selector valve directly communicates with the outside air is formed to be relatively long. There is no possibility of muddy water scattering around the third port from the intake side.

By the way, the exhaust brake operates intermittently, and a certain amount of air is sufficient for one exhaust brake operation, but in this invention, as mentioned above, the switching valve is connected to a path that directly communicates with the outside air. In addition to being set relatively long, the rear cab mount pipe has a relatively large diameter, so the amount of air required for one activation of the exhaust brake depends on the air accumulated in the rear cab mount pipe. I can cover enough.

Therefore, when the exhaust brake is activated, outside air is hardly introduced directly into the exhaust brake switching valve, making it unnecessary to install an air filter.

In addition, since the air intake is provided at the lower end of the other hollow leg, even if muddy water, etc. is splashed into the hollow leg from the air intake, it will fall naturally and will not flow into the rear cab mount pipe. It is less likely that foreign matter will enter the air.

As described above, this invention has the advantages of a rational and simple structure, low cost, and excellent practicality.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a schematic rear view of the vehicle, FIG. 2 is a side view, FIG. 3 is an exhaust pipe system diagram of an exhaust brake, and FIG. 4 is a partially cutaway front view showing an enlarged view of the main parts. 7... Rear cab mount pipe, 13... Exhaust pipe, 14... Exhaust brake, 16... Actuator, 17... 3-way magnetic valve (switching valve), 21... First port, 22... Second port, 23...Third port, 25...Vacuum tank, 29...Atmospheric intake, 7a...Hollow leg portion, 7b...Hollow beam portion, 30...Cap.

Claims (1)

[Scope of utility model registration request] The exhaust brake switching valve has a first port connected to the vacuum tank, a second port connected to the actuator of the exhaust brake valve, and a third port communicating with the atmosphere. In a device that switches communication between the first and second ports and communication between the second and third ports by turning on and off, the left and right hollows are fixed to the left and right chassis frames of the vehicle and extend above the chassis frames. A portal-shaped hollow rear cab mount pipe is provided, which has a hollow beam section that connects the upper ends of the left and right hollow legs to communicate the two hollow legs. A third port of the switching valve is communicated with an intermediate portion of one hollow leg of the rear cab mount pipe, and a cap for preventing muddy water from entering is attached to the lower end of the one hollow leg,
An atmosphere intake structure for an exhaust brake switching valve, characterized in that the lower end of the other hollow leg portion is opened to serve as an atmosphere intake port.