JPS6237031Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vehicle fuel relief valve that is used in a motor-driven vehicle fuel feed pump to adjust a suitable discharge pressure.

Normally, this type of fuel pump has a sufficient capacity so that it can pump a sufficient amount of fuel to meet the demand even when the engine is consuming the maximum amount of fuel. There is a risk that more fuel will be discharged than the engine requires, causing fuel overflow in the carburetor. To prevent this, when the fuel discharge pressure exceeds a specified value, a relief valve opens and some of the fuel returns from the discharge side to the suction side. For example, a structure as shown in Figure 1 is generally available. It will be done. In the figure, three main components surrounded by a casing 1 arranged one after the other in the axial direction are a compartment type pump 3 having an inlet 2 and a movement of the compartment type rotary pump 3. A DC motor 4 that drives the member, allows the fuel discharged from the compartment type rotary pump 3 to penetrate therein, and has a discharge port 5, and further opens when the fuel pressure exceeds a specified value, allowing part or all of the fuel to flow to the discharge side. The relief valve 6 is configured to return to the suction side.

In the case of this invention, the compartment type rotary pump 3 and the DC motor 4 are not essential, but the relief valve 6 is important, so this part will be explained in detail.

FIG. 2 is a sectional view showing a conventional relief valve. In the figure, 61 is a rubber valve body having a hemispherical head and a cylindrical foot protruding from the center of the plane, and 63 is a cylindrical valve hole, one of which is the head of the valve body 61. It has a small-diameter tapered valve seat 62 that comes into contact with the valve seat 62 to prevent fluid flow. 64
A coil spring has one end wound around the foot of the valve body 61, and the other end of the coil spring 64 is in contact with a stopper 65. This stopper 65 is provided with a hole or notch that allows fluid to flow therethrough, and is caulked and fixed to the other opening of the valve hole 63. The coil spring 64 is formed into a tapered shape that determines the valve opening value, and the head of the valve body 61 is placed on the side of the DC motor 4 (see FIG. 1), and the foot of the valve body 61 is placed on the suction side of the rotary pump 3. It is arranged so that it communicates with the side.

In the conventional relief valve, when the discharge pressure of the pump increases, the valve body 61 moves against the tension force of the coil spring 64, and the head of the valve body separates from the valve seat 62. This allows fuel to flow around the valve body. However, since the fluid resistance of the flow of fuel is not necessarily uniform around the valve body, a force that gently rotates the valve body 61 acts, causing the valve body 61 to perform an oscillating motion and receive the rotational force to cause the coil spring 64 to rotate. However, conventionally the stopper 65
Since a hollow iron plate is used as the valve body, rotation is prevented by a large frictional force between the coil spring and the stopper, which further promotes the swinging movement of the valve body 61. The disadvantage was that stable operation could not be performed.

This idea was made in order to eliminate the above-mentioned conventional drawbacks. One end of the coil spring is wound around the foot of the valve body, and the other end of the coil spring is replaced by a stopper made of resin that has lubricity and wear resistance. An object of the present invention is to provide a relief valve for a vehicle fuel pump which has excellent stability and durability by being supported by a fuel pump.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 3, the valve hole 63 is formed in a cylindrical shape like the coil spring 64, and the taper angle δ of the valve hole 63 is larger than the taper angle γ of the coil spring 64. Further, a ring-shaped protrusion 66 is provided on the inner wall near the wide-diameter side entrance of the valve hole 63. Reference numeral 65 denotes a stopper, which is made of resin such as plastic in consideration of lubricity, wear resistance, and oil resistance. This stopper 65 has a ring-shaped V groove 101 shown in FIG. 4, which is formed into a ring shape into which one end of the coil spring 64 fits and restricts the movement of the coil spring 64 in the radial and axial directions, and the center portion thereof is penetrated. A fluid circulation hole 102, locking claws 103 having elastic force in the radial direction provided at eight locations on the outer periphery, a groove 104 for allowing fluid to flow, and a post 105 are formed, respectively.

The stopper 65 having the above structure shown in FIG. 3 is fixed by the locking pawl 103 being hooked on the ring-shaped protrusion 66. That is, when the stopper 65 is inserted, when the locking pawl 103 comes into contact with the protrusion 66, it is displaced inward, the locking pawl 103 passes through the protrusion 66, and then returns to its original state due to elasticity. In this state, stopper 6
When the insertion force 5 is removed, the stopper 65 is pushed back by the extension force of the stopper 65, and the locking pawl 103 is caught on the protrusion 66 and fixed. Note that the force with which the locking pawl 103 engages the protrusion 66 is not absolute, and if an excessive external force is applied (for example, by inserting a metal object into the gap 67 and prying the stopper 65), the locking claw 103 will be removed. This allows reuse, that is, replacement of the coil spring 64 and stopper 65.

The operation of the above configuration will now be described. When power is supplied to the DC motor 4 (see Fig. 1), the moving member of the compartment pump 3 is driven, and fuel is sucked in from the suction port 2, passes through the space of the DC motor 4, and enters the engine via the discharge port 5. About to be sent. If the engine is in a state where it can receive a sufficient supply of fuel, the pump will discharge the fuel, and since the fuel pressure inside the motor is low, the top of the valve body 61 will be moved toward the valve seat 6 by the expansion force of the coil spring 64. The relief valve 6 is in a closed state.

Next, when the engine does not need enough fuel, the amount of oil fed by the pump is greater than the consumption, and the pump discharge pressure increases, so the valve body 61 resists the expansion force of the coil spring 64. The head of the valve body 61 is moved away from the valve seat 62. As a result, the valve opens and the fuel on the discharge side of the pump returns to the suction side via the fluid communication hole 102 or the groove 104, thereby functioning as a pressure regulating valve to prevent the pressure on the discharge side from increasing.

The above configuration has the following effects compared to the conventional example.

Since the stopper 65 is made of a resin having lubricating properties and wear resistance, the sliding friction between the coil spring 64 and the stopper 65 is significantly reduced, so that the coil spring 64 and the valve body 61 can rotate smoothly. This reduces the swinging movement of the valve. Further, the friction between the end face of the coil spring 64 and the stopper 65 is also significantly reduced.

Since the stopper 65 is removable, the coil spring 64 can be replaced even if the valve opening value deviates from the specified pressure, and its construction is simple and inexpensive.

As described above, according to this invention, one end of the coil spring is wound around the foot of the valve body, and the other end of the coil spring is supported by a stopper made of a resin having lubricating properties and wear resistance. Swinging motion of the body, twisting of the coil spring, etc. are eliminated, and wear of the end face of the coil spring and the stopper is reduced, so that stable relief operation can be performed.

Further, a ring-shaped protrusion is provided on the inner wall near the outlet side of the valve hole, and a ring-shaped groove into which the other end of the coil spring is fitted is provided on the end face of the stopper. By providing an elastic locking pawl that engages with the shaped protrusion and prevents the movement of the stopper, the stopper can be easily removed and the coil spring can be easily replaced, resulting in excellent practical effects. It is something.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an automobile fuel supply pump using a relief valve, Fig. 2 is a sectional view of a conventional relief valve, Fig. 3 is a sectional view of a relief valve showing an embodiment of this invention, and Fig. 4 is a sectional view of an automobile fuel supply pump using a relief valve. The figure shows the main parts of the relief valve shown in Figure 3, Figure 4a,
Figures b and 4c are a plan view, a partial sectional view, and a bottom view, respectively. 6... Relief valve, 61... Valve body, 62...
... Valve seat, 63 ... Valve hole, 64 ... Coil spring, 65 ... Stopper, 66 ... Projection, 67 ...
...Gap, 101...V groove, 102...Fluid circulation hole, 103...Latching claw, 104...Groove, 105...
…post. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A valve body having a substantially hemispherical head and a foot protruding from the central plane thereof, a valve seat having a valve hole having a tapered portion with which the head of the valve body abuts, and a foot portion of the valve body. A coil spring having one end wound around the coil spring to press the valve body against the valve seat, and a stopper supporting the other end of the coil spring, wherein the valve hole is formed on an inner wall near the outlet side of the coil spring. In addition to providing a ring-shaped protrusion, the stopper is formed of a resin having lubricity and wear resistance, and has a ring-shaped groove on its end surface into which the other end of the coil spring is inserted, and a ring-shaped groove on its outer periphery. 1. A relief valve for a vehicle fuel pump, comprising an elastic locking pawl that engages with a shaped protrusion to prevent movement of the stopper.