JPH068749U - Solenoid valve for slow fuel cut of vaporizer - Google Patents

Abstract

(57) [Abstract] [Purpose] When the vehicle is decelerating when the engine speed is high, the needle (valve element) of the closed solenoid valve vibrates due to the vibration of the engine and does not come into close contact with the valve seat. Prevent it from leaking. [Structure] When the vehicle is decelerated, the first coil 2 is de-energized, and the needle 16 is pressed against the valve seat 20 by the load of the spring 10 to close the valve. Immediately after this, or when the first coil is de-energized, the second coil 3 is energized and excited, and the second stator 14 attracts the second plunger 18. Due to this suction force, the needle 16 more firmly adheres to the valve seat 20 and surely cuts the slow fuel. [Effect] The needle 16 is prevented from swinging due to engine vibration, and the leakage of slow fuel is prevented. As a result, burnout of the exhaust purification catalyst is eliminated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a solenoid valve used to control the opening and closing of the slow fuel passage of a car carburetor.

[0002]

[Prior art]

 In a car carburetor for gasoline, a solenoid valve that opens and closes the slow fuel passage is provided in the middle of the slow fuel passage, and when the vehicle decelerates, the solenoid valve is closed to perform slow fuel cut for purifying exhaust gas. (See, for example, Japanese Utility Model Publication No. 57-22654, FIG. 2).

This type of slow fuel cut solenoid valve cuts off the slow fuel by shutting off the exciting current when the vehicle is decelerating and pressing the needle (valve body) against the valve seat with a spring to close the solenoid valve.

[0004]

[Problems to be solved by the device]

 In the above conventional technology, when the engine speed is high when the vehicle is decelerated, a large vibration of the engine body is transmitted to the solenoid valve, and the needle (valve element) swings. The solenoid valve will not be able to seal because it will not adhere to.

Then, there is a problem that fuel leaks into the slow passage and flows, and the catalyst burns out. In order to deal with this, if the force of the spring that presses the needle (valve body) against the valve seat is increased, it is necessary to enlarge the exciting coil for opening the valve against the spring, and the solenoid valve is There is a new problem that it is not practical because it takes shape.

Therefore, in view of the above, the present invention prevents slow fuel leakage due to engine vibration and solves the above problems without increasing the size of the solenoid valve. The purpose is to provide a valve.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the slow fuel cut solenoid valve of the carburetor according to the present invention energizes the first coil (2) during normal traveling of the vehicle and resists the spring (10) against the needle ( 16) is opened apart from the valve seat (20) and at the time of vehicle deceleration, the first coil (2) is de-energized and the spring (10) causes the needle (16) to move to the valve seat (20). In a solenoid valve that is pressed and closed, a second coil (3) that presses the needle (16) against the valve seat (20) by magnetic force due to energization is provided, and the second coil (3) is energized during vehicle deceleration. It was configured to excite.

[0008]

[Action]

 During normal traveling of the vehicle, only the first coil (2) is energized and excited, and the needle (16) separates from the valve seat (20) and opens the valve against the spring (10).

During deceleration of the vehicle, only the second coil (3) is energized and excited, and the magnetic force and the force of the spring (10) both force the needle (16) against the valve seat (20). It is pressed and closes with a strong force.

Therefore, the needle (16) is not shaken by the vibration of the engine, and the fuel is prevented from leaking and flowing through the slow passage.

[0011]

【Example】

 In the embodiment of FIG. 1, reference numeral 1 denotes a resin-molded bobbin, which is provided with two coil winding portions, and a first coil 2 and a second coil 3 having different numbers of turns are wound. There is. The winding start ends of the first and second coils 2 and 3 are connected to the terminals 4 and 5 by soldering together with the first and second harnesses 6 and 7.

Reference numeral 8 is a metal plate, and the winding ends of both coils 2 and 3 are connected to this plate 8. Reference numeral 9 is a first stator formed by cutting a magnetic material, and a housing hole for the spring 10 is formed in the center thereof.

Reference numeral 11 denotes an O-ring fitted in a groove on the outer circumference of the first stator 9 to prevent fuel from leaking from the inside to the outside of the solenoid valve. Reference numeral 12 is an earth plate, which is fixed to the right end of the stator 9 together with the plate 8 by caulking.

The plate 8 is formed by pressing an iron-based magnetic material so that it also functions as a yoke of a magnetic circuit. Further, the earth plate 12 is elastically brought into contact with the inner peripheral surface of the housing 13 by using a conductive material having elasticity in order to secure electrical connection with the inner peripheral surface of the housing 13.

The first stator 9 is inserted inside the bobbin 1 with the plate 8, the ground plate 12 and the O-ring 11 attached. The housing 13 is made of a magnetic material so as to form a yoke of a magnetic circuit, and the left half small diameter portion of the second stator 14 made of the same magnetic material is press-fitted and fixed to the housing 13.

Reference numerals 15A and 15B denote auxiliary electrodes of the first and second coils 2 and 3, which are horseshoe-shaped, and are both inserted from the side surface of the bobbin 1 and crimped. Reference numeral 16 is a needle (valve body) that slidably fits the housing 13 and the second stator 14. Reference numerals 17 and 18 denote first and second plungers made of a magnetic material, which are fitted to the needle 16 together with a spacer 19 made of a ring-shaped non-magnetic material and fixed by caulking around the needle insertion hole. .

The spacer 19 acts to block the magnetic path between the two plungers 17 and 18. At the left end of the housing 13, there are formed a screw portion 13a for attaching the solenoid valve to the carburetor, and a hexagonal portion 13b for applying a spanner at the time of attachment.

Reference numeral 20 denotes a valve seat, which has a tubular shape as a whole, the right end portion of which is press-fitted and fixed to the housing 13 and which cooperates with a taper portion 16 a formed at the tip (left end in the drawing) of the needle (valve body). It has a working seat surface 20a.

The fuel is controlled by the tapered portion 16 a of the needle 16 and the seat surface 20 a of the valve seat 20 on the way from one inlet 20 b of the valve seat to the other outlet 20 c.

Reference numeral 21 denotes a resin plate on which the first and second terminals 4 and 5 are insert-molded. An O-ring 22 is sealed by the three surfaces of the bobbin 1, the housing 13 and the second stator 14 to prevent fuel from leaking to the outside of the solenoid valve.

Reference numeral 23 denotes a rubber cover. In order to prevent water from entering from the outside, the first and second harnesses 6 and 7 are passed through the cover 23, and the cover 23 is further inserted into the bush 24.

Reference numeral 24 is a bush formed of a resin molded product, and an O-ring 25 for preventing invasion of moisture from the outside is attached to the outer circumference of the bush to seal the inner circumference of the housing 13. .

Reference numeral 26 denotes a cylindrical retainer, which is fitted into the needle 16 and is sandwiched between the spring 10 and the first plunger 17 by being pressed by the force of the spring. The above internal parts are housed in the housing 13, and the housing 13 is fixed by caulking the housing 13 at the right end corner of the bush 24.

Reference numeral 27 is an O-ring fitted on the outer periphery of the valve seat 20, and secures a seal between the inlet 20b and the outlet 20c of the slow fuel passage with a carburetor body (not shown).

Next, the operation of the above embodiment will be described. When the engine is stopped, both coils 2 and 3 are not excited, and the spring 10 presses the tip taper portion 16a of the needle 16 against the seat surface 20a of the valve seat 20 to close the slow fuel passage.

When the engine is started, a voltage is applied between the first harness 6 and the housing 13 from a control circuit (not shown), and the first coil 2 is energized and excited. Then, a magnetic flux flows through the magnetic circuit including the housing 13, the auxiliary magnetic pole 15A, the first plunger 17, the first stator 9, and the plate 8, the first plunger 17 is attracted to the first stator 9, and the needle 16 The tapered portion 16a of the valve seat 20 separates from the seat surface 20a of the valve seat 20, and the slow fuel passage opens.

This valve opening operation continues during normal traveling after the engine is started. Next, when the vehicle is decelerated, the control circuit (not shown) cuts off the power supply to the first coil 2.

Then, the suction force between the first stator 9 and the first plunger 17 becomes almost zero, and the needle 16 is pressed against the valve seat 20 by the load of the spring 10 to close the valve. Immediately after this, or when the control coil (not shown) energizes the second coil 3 at the same time when the first coil is de-energized, the second stator 14 attracts the second plunger 18. The needle 16 more strongly against the valve seat 20 to securely close the valve.

In this state, the needle 16 is strongly pressed by the sum of the load of the spring 10 and the suction force of the second stator 14 and the second plunger 18, so that even if the engine speed is high, Due to the vibration, the taper portion 16a of the needle 16 is not vibrated, and the slow fuel leakage of the solenoid valve due to the engine vibration is prevented.

When the vehicle returns to normal running after deceleration, the second coil is de-energized and the first coil is re-energized to open the solenoid valve.

[0031]

[Effect of device]

 Since the slow fuel cut solenoid valve of the carburetor according to the present invention is configured as described above, the second stator (14) and the second plunger () are added to the load of the spring (10) when the vehicle is decelerated. Since the magnetic force of 18) strongly presses the needle 16 against the valve seat 20, the needle will not shake due to engine vibration even during deceleration at high engine speed, and the slow fuel will not leak. Therefore, the catalyst burned out.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

[Explanation of symbols]

 2 1st coil 3 2nd coil 10 Spring 16 Needle 20 Valve seat

─────────────────────────────────────────────────── ───Continued from the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F16K 31/06 385 A 7214-3H

Claims (1)

[Scope of utility model registration request] 1. When the vehicle is traveling normally, the first coil is energized, the needle is separated from the valve seat against the spring to open the valve, and the first coil is de-energized when the vehicle is decelerated. In the solenoid valve that presses the needle against the valve seat by the spring to close the valve seat, a second coil that presses the needle against the valve seat with an electromagnetic force generated by energization is provided, and the second coil is energized when the vehicle is decelerated. Solenoid valve for slow fuel cut of carburetor configured as above.