JPS6332354Y2 - - Google Patents

Description

[Detailed description of the invention] In order to prevent lubricating oil consumption from increasing when the engine decelerates, this invention bypasses the throttle valve installed in the intake passage and introduces air downstream to reduce engine intake negative pressure. This invention relates to a deceleration control valve during deceleration of an internal combustion engine that is designed to prevent excessive deceleration (see Utility Model Application No. 54-61125).

When the engine decelerates, the suction negative pressure on the downstream side of the throttle valve becomes excessive, and lubricating oil is sucked into the combustion chamber from around the piston, or from the rocker room around the valve stem and into the intake passage, causing lubrication. Oil consumption increases significantly. Therefore, a deceleration control valve as shown in FIG. 1 has been proposed. That is, a bypass passage 4 is provided in the intake passage 2 of the engine 1 to bypass the throttle valve 3, and when the differential pressure between the suction negative pressure on the downstream side of the throttle valve 3 and the pressure on the upstream side exceeds a predetermined value, A deceleration control valve 5 that opens is provided. In the figure, 6 is an air flow meter, 7 is a fuel injection valve that injects and supplies fuel into the intake passage 2, and 8 is an exhaust passage.

Conventionally, the deceleration control valve described above has a valve case 11 screwed into the intake passage 2, as shown in FIG.
While further screwing the valve seat 12 into the valve case 11,
A return spring 15 guided by a spring guide 14 is interposed between the valve body 13 that opens and closes the valve seat 12 and the valve case 11. Since the installation length of the return spring 15 is kept unchanged, the opening and closing of the deceleration control valve is The valve pressure fluctuates greatly due to variations in the set load of the return spring 15, and it has been difficult to set it uniformly within a narrow allowable valve opening load range (-570 to -600 mmHg).

Of course, even with this conventional configuration, the valve seat 12 can be rotated to adjust the relative position with respect to the valve case 11 and the mounting length of the return spring 15 can be made variable. Unauthorized modification may result in a change in valve opening pressure, resulting in poor operability or noise and wear caused by opening and closing of the valve body 13.

Further, the valve case 11 and the spring guide 14 as spring receivers are made of metal, and therefore interference between these and the return spring 15 may cause abnormal noise.

The present invention solves the inconveniences of the conventional device by screwing a synthetic resin spring seat into a metal support fixed in the case so that it can move forward and backward, and a spring whose one end is locked to the spring seat. The valve body is seated on the valve seat at the upstream entrance of the bypass passage of the case by elastic force, and a groove is formed in a part of the spring seat screwing part of the support, and the spring seat is rotated to open the valve at a predetermined value. At the same time, by heating and deforming the synthetic resin spring seat in the groove and engaging and fixing it, the valve opening pressure can be set accurately and the valve opening pressure can be configured to remain unchanged without being tampered with. To provide a deceleration control valve that prevents variations in valve opening pressure among individual valves, eliminates poor drivability caused by unauthorized modification, and prevents abnormal noises caused by interference between metals.

An embodiment of the present invention will be described below with reference to FIG. On the wall of the intake passage 2, there is a downstream case part 21.
The entire case is constructed by screwing in the threaded portion 21a provided on the outer periphery of the outlet side opening of the case, and caulking the upstream case portion 22 made of sheet metal to the other end of the downstream case portion 21. And these two case parts 2
Perforated collar part 2 of metal support 23 between 1 and 22
3a is held between the female threaded part 24 provided on the inner periphery of the cylindrical support part 23b at the center of the support 23, and the male threaded part 2 provided on a part of the outer periphery of the spring seat 25 made of synthetic resin.
6 can be screwed together freely. At this time, a deformed groove 27 consisting of a groove having a shape other than a thread is previously formed in a part of the female threaded portion 24 on the inner periphery of the cylindrical support portion.

In addition to the male threaded portion 26, the spring seat 25 includes a guide portion 28 that extends toward the upstream side of the intake bypass, and its upstream end faces the valve body 30.

A spring 3 interposed between the valve body 30 and the spring seat 25
1, the valve seat 32 of the upstream case portion 22 faces toward the upstream side of the bypass passage. The valve seat 32 is made of an elastic sealing material such as rubber,
The edge of the inlet side opening of the upstream case portion 22 is covered.

The valve body 30 is formed of a plate-shaped body made of stainless steel,
As shown in FIG. 3C, it has a convex edge 30a that slides on the inner wall surface of the upstream case portion 22, and a notch portion 30b that forms an air passage between the inner wall surface of the case portion and the inner wall surface of the case portion.

Further, as shown in FIG. 3B, an engagement recess 35 is formed in the downstream end surface of the spring seat 25 so that an adjustment tool can be engaged and rotated therein.

Therefore, according to the above structure, when the adjustment tool is engaged with the engagement recess 35 and the case parts 21 and 22 are rotated, the spring is released against the support 23 due to the threaded relationship between the support 23 and the spring seat 25. The seat 25 moves back and forth in the axial direction, and the spring 31 between the spring seat 25 and the valve body 30
When the differential pressure between the suction negative pressure on the downstream side of the valve body 30 (the suction negative pressure downstream of the throttle valve 3) and the pressure on the upstream side exceeds a predetermined value, the elastic force of the spring 31 is The valve opening pressure at which the valve body 30 rises can be adjusted. After such adjustment, the cylindrical support part 2 of the support 23
3b, the outer periphery corresponding to the deformation groove 27 or the engagement recess 35 direction is the male threaded portion 2 of the spring seat 25 near the deformation groove.
6 is heated with, for example, an electric heating iron or the like to thermally deform the external threaded portion 26 of the spring seat 25 made of synthetic resin. As a result, a part of the spring seat 25 enters into the deformation groove 27 and gets caught between the support 23 and the spring seat 25.
The spring seat 25 is prevented from rotating thereafter. This is possible without using caulking means, so the support 23 or the spring seat 25
No unnecessary deforming force is applied to the valve, and therefore the once adjusted valve opening pressure will not be disturbed.

Further, since the guide portion 28 integrated with the spring seat 25 is made of a synthetic resin material, it has the advantage of reducing interference noise between the spring 31 and the guide portion 28.
By coming into contact with the valve seat 32, the upstream end surface of the valve can function as a stopper that limits its rise and regulates the maximum lift amount of the valve body. It is possible to prevent the electronically controlled fuel injection engine from running out of control or having poor drivability.

Next, the operation of the above embodiment will be explained in relation to FIG.

Intake air to the engine passes through an air cleaner/air flow meter 6 and a throttle valve 3, and is introduced into the engine 1 through an intake passage 2. When the throttle valve 3, which is connected to an accelerator pedal (not shown), is held at a deceleration position, for example, a fully closed position while driving, the suction negative pressure on the downstream side of the throttle valve 3 rises, and the differential pressure with the pressure on the upstream side of the throttle valve increases. When the value corresponding to the set load of the spring 31 of the deceleration control valve 5 is greater than, for example, -570 mmHg, the valve body 30
1 and guides the intake air into the bypass passage 4 and introduces it into the intake passage 2 downstream of the throttle valve 3, thereby suppressing an excessive rise in intake negative pressure in the passage 2. Therefore, the amount of lubricating oil drawn into the combustion chamber or intake passage from around the piston or around the valve stem is not increased.

Note that if the upstream inlet opening area of the deceleration control valve 5, the effective passage area of the perforated brim 23a of the support, and the downstream outlet opening area of the deceleration control valve 5 are designed to be large in this order, favorable valve opening characteristics such as responsiveness can be achieved. Obtained. Furthermore, by synchronizing the opening timing of the valve body 30 with the fuel supply stop timing of the fuel injection valve 7, the engine output is cut, and the pumping loss of the piston is reduced by preventing the suction negative pressure from increasing. Effective engine braking can be achieved.

As described above, according to the present invention, a synthetic resin spring seat is screwed into a metal support fixed in the case so that it can move forward and backward, and the spring mounting length can be adjusted by rotating the spring seat. As a result, the valve opening pressure can be adjusted freely, and the spring mounting length can be fixed after the adjustment by heating and deforming the spring seat made of synthetic resin and locking it in the groove of the spring seat screwing part. Since the spring installation length is fixed accurately and within the allowable value after adjustment, valve opening pressure fluctuations due to variations in spring assembly can be prevented, and the adjusted value is fixed, improving deceleration characteristics and The lubricating oil consumption characteristics can be made uniform without the adverse effects of changes over time. In addition, since the spring mounting length is adjusted inside the valve case, which cannot be tampered with from the outside, stable valve characteristics can be maintained.Furthermore, the spring seat made of synthetic resin is located between the spring and the spring. Less likely to generate interference noise.

[Brief explanation of drawings]

Figure 1 is a schematic system diagram showing a general reduction gear.
Fig. 2 is a longitudinal cross-sectional view of a conventional deceleration control valve used in the same as above, Fig. 3 shows an embodiment of the present invention, A is a longitudinal cross-sectional view, B is a top view of A, and C is a valve of the same as above. FIG. 1...engine, 2...intake passage, 3...throttle valve,
21, 22...Case part, 23...Support, 2
3b...Cylindrical support part, 24...Female screw part, 25...
...Spring seat, 26...Male thread part, 27...Deformation groove,
28... Guide portion, 30... Valve body, 31... Spring, 32... Valve seat.

Claims (1)

[Scope of utility model registration request] A deceleration control valve that is installed in a bypass passage that bypasses a throttle valve in an intake passage and opens when a differential pressure between an intake negative pressure downstream of the throttle valve and an upstream pressure is equal to or higher than a set value, and is fixed in a case. A synthetic resin spring seat is screwed into a metal support that can freely move forward and backward, and the elastic force of the spring, one end of which is locked to the spring seat, causes the valve body to sit on the valve seat at the upstream entrance of the bypass passage of the case. At the same time, a groove is formed in a part of the spring seat screwing part of the support, and while the spring seat is rotated to adjust the valve opening pressure to a predetermined value, the synthetic resin spring seat is heated and deformed in the groove. A deceleration control valve for an internal combustion engine, characterized in that the deceleration control valve is engaged and fixed.