JPS6133250Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present application relates to a vacuum motor for an intake air temperature control device for an internal combustion engine.

As shown in Fig. 2, the intake air temperature control device is for adjusting the temperature of the intake air sent to the engine within a predetermined range, and includes a switching valve 21 attached to a vacuum motor 20 that is operated by negative pressure generated in the engine. This is done by opening and closing the hot and cold air channels 22 and 23 of the suction pipe 24. Vacuum motor 2
A temperature-sensitive valve is provided between 0 and a negative pressure source of the engine, such as an intake pipe. A normal vacuum motor 20 used in this device consists of a diaphragm stretched inside a case, and when a predetermined negative pressure is applied to the diaphragm surface, a switching valve 21 connected to the diaphragm via a spindle is operated up and down. However, depending on the operating state of the engine, a negative pressure far exceeding the predetermined negative pressure value, for example, about -650 mmHg, will act on the diaphragm. When such a large negative pressure is applied, the vacuum motor 20
Alternatively, there is a possibility that the switching valve 21 may be destroyed. In order to avoid this, it may be possible to provide a separate negative pressure cut valve that acts to cut off the negative pressure when the negative pressure inside the vacuum motor exceeds a predetermined level. The vacuum motor stops operating as soon as the cut is made, and the structure becomes complicated.

Therefore, the present application provides a vacuum motor for an intake air temperature control device that controls the maximum value of negative pressure applied to the vacuum motor and improves durability.

To explain the embodiment, FIG. 1 shows a vacuum motor 10 of the present invention, in which a chamber formed by upper and lower valve cases 1 and 2 is connected to a first chamber 5, a second chamber 6, and a chamber formed by a diaphragm assembly 3 and a spring retainer 4. The third room is divided into 7, and the first room is 5.
A bypass valve 8 is formed in the. The diaphragm assembly 3 is made by integrating an elastic diaphragm 9 and a retainer 11, has a spindle 12 in the center to which a switching valve (not shown) is attached, and has an outer periphery formed by the upper and lower valve cases 1 and 2.
held between. The spring retainer 4 has a communication port 13 and is fixed to the inner upper wall of the upper valve case 1. The first chamber 5 is provided with a bypass valve 8 consisting of a valve body 14 and a compressed spring 16 between the valve body and the spring retainer 4. 17
Close. In the second chamber 6, a spring 18 is compressed between the diaphragm assembly 3 and the spring retainer 4, and a negative pressure pipe 19 is attached to the side wall of the valve case 1. The third chamber 7 is provided with an opening 15 that communicates with the atmosphere and into which the spindle 12 is inserted. The upper wall of the first chamber 5 has a restricted flow path 17.
A negative pressure pipe 20 is provided which communicates with the interior of the room via the vacuum pipe 20 . Here, the valve opening pressure of the bypass valve 8 is the second
The value is set to be greater than the value required for the diaphragm assembly 3 in the chamber 6 to rise completely against the spring 18 to its maximum limit.

The vacuum motor 10 having the above configuration is attached to the intake pipe of an air cleaner provided with a hot/cold air port, as in the conventional one shown in FIG. The pressure pipes 19 are each connected to a negative pressure source of the engine via a temperature sensitive valve (not shown) and put into use.

When the temperature of the intake air introduced from the intake pipe is higher than a predetermined value, the temperature-sensitive valve opens and the negative pressure of the negative pressure source is transferred to the negative pressure pipe 1.
9 to the vacuum motor 10. When the intake temperature falls below a predetermined value, the temperature-sensitive valve closes and the negative pressure from the negative pressure source is transmitted from the negative pressure pipe 19 into the vacuum motor 10 to raise the diaphragm assembly 3 against the spring 18. When the negative pressure increases and the diaphragm assembly 3 reaches its upper limit, the valve body 14 in the first chamber 5, which is communicated with through the communication port 13,
It descends against the spring 16 and opens the restricted flow path 17, through which the atmosphere is introduced into the room. the result,
Even if the negative pressure of the negative pressure source increases, the negative pressure within the vacuum motor 10 does not rise any further, is regulated to a predetermined value, and is not eliminated. Therefore, the spindle 12 of the vacuum motor 10 is maintained at substantially the same position. When the negative pressure in the negative pressure source decreases, the bypass valve 8 closes to reduce the negative pressure in the vacuum motor, lowering the spindle 12, and as the negative pressure in the negative pressure source increases, the negative pressure in the vacuum motor 10 is gradually reduced again. to rise to.

As described above, the vacuum motor of the present invention is equipped with a bypass valve that opens when the negative pressure inside the motor exceeds the necessary value, that is, the negative pressure value that moves the diaphragm assembly to the maximum limit, and a restriction flow path. Therefore, the negative pressure inside the vacuum motor can be adjusted to a low pressure without inhibiting the operation of the vacuum motor, and the durability is improved without applying excessive force to the valve member. Further, since the vacuum motor has an integral mechanism that prevents the negative pressure from increasing more than necessary, it is extremely simple.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a vacuum motor according to the present invention, and FIG. 2 is a cross-sectional view of an intake air conditioning device equipped with a conventional vacuum motor. 1, 2... Upper and lower valve cases, 5... First chamber,
8... Bypass valve, 17... Restricted flow path.

Claims (1)

[Scope of utility model registration request] The chamber formed by the upper and lower valve cases is separated by a spring retainer with a communication port and a diaphragm assembly with a spindle in the center.
The first chamber is sequentially divided into a first chamber, a second chamber, and a third chamber, and a restriction flow path is provided on the upper wall of the first chamber, and a bypass valve consisting of a valve body and a spring is disposed within the first chamber.
The restriction flow path is closed with a valve body, a negative pressure pipe is provided on the side wall of the second chamber, and a spring is compressed between the spring retainer and the diaphragm assembly, so that the opening pressure of the bypass valve is set to the maximum limit by the diaphragm assembly. A vacuum motor of an intake air temperature control device is set to a value higher than the negative pressure value required to move the air to the atmosphere, and the third chamber is communicated with the atmosphere.