JP2021169790A - Purge valve - Google Patents

Abstract

To provide the most desirable structure of a purge valve with a flow straightener.SOLUTION: A valve seat passage, in which a passage sectional area gradually increases from a throttle part at a valve seat position, is formed within a valve seat member, and an outflow port communicating with the valve seat passage is formed by a cylindrical laser light permeable resin. Further, a flow straightener formed by a columnar laser light absorption resin and having a flow straightening passage is inserted from a tip part of the outflow port. The passage sectional area is increased in the valve seat passage and the valve seat passage communicates with the outflow port. Then, the passage sectional area is contracted in the flow straightening passage. The flow straightening passage inhibits occurrence of vortex flow in the valve seat passage and an abnormal noise reduction effect of the flow straightener is attained. Further, an insertion taper part is formed protruding at one end of the flow straightener, a positioning flange part is formed protruding at the other end, and a welding taper part is formed protruding in an intermediate part. In a state that the flow straightener is inserted into the outflow port, the welding taper part of the flow straightener and the outflow port are welded by laser light.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a purge valve that opens and closes the purge passage, which is interposed between the canister and the intake passage.

Patent Document 1 describes that a rectifier for reducing abnormal noise caused by evaporated fuel or air flowing through a purge passage is provided at an outlet of a purge valve. However, Patent Document 1 does not describe the internal structure of the purge valve and the mounting structure of the rectifier.

On the other hand, an inlet port, a valve chamber, a valve body, a valve seat passage, and an outlet port are formed inside the purge valve, and the fluid flow inside the purge valve is complicated. Moreover, even when the rectifier is provided, it is necessary to efficiently exert the abnormal noise reduction effect of the rectifier.

JP-A-2019-143564

In view of the above points, it is an object of the present disclosure to provide the most desirable configuration of a purge valve incorporating a rectifier.

The first of the present disclosure is a coil that excites when energized, a stator made of a magnetic material, a plunger that is arranged to face the stator via a magnetic gap, a valve body that moves together with the plunger, and the valve body. It is a purge valve including a valve seat that comes into contact with the valve seat and a compression spring that presses the valve body toward the valve seat side. Further, the first purge valve of the present disclosure includes an inflow port for inflowing evaporative fuel and air from the canister, a valve chamber communicating with the inflow port, and a cylindrical valve seat member arranged in the valve chamber. It has a valve seat located at the tip of the valve seat member and an outflow port for discharging evaporated fuel and air to the intake passage side.

In particular, in the first purge valve of the present disclosure, a valve seat passage in which the passage cross-sectional area gradually increases from the valve seat is formed inside the valve seat member, and the passage cross-sectional area at the valve seat portion position of the valve seat passage is minimized. It forms a squeezed part. Then, an outflow port that communicates with the maximum portion of the passage cross-sectional area of the valve seat passage is provided, and this outflow port is formed of a cylindrical laser light transmitting resin. Further, a rectifier formed of a cylindrical laser light absorbing resin and having a rectifying passage inside is inserted from the tip of the outflow port. The total passage cross-sectional area of the rectifying passage is smaller than the passage cross-sectional area of the outflow port.

After increasing the passage cross-sectional area in the valve seat passage, it communicates with the outflow port and a rectifier is arranged in the outflow port, so that the flow of fuel vapor and air can be throttled in the rectifier passage of the rectifier. Therefore, the rectifier can suppress the generation of vortex flow in the valve seat passage downstream of the throttle portion, and can enhance the effect of reducing abnormal noise of the rectifier.

In the first purge valve of the present disclosure, a tapered portion for insertion is formed at one end of the rectifier so as to protrude from the outer peripheral surface, and a flange portion that contacts the tip of the outflow port is formed at the other end so as to protrude from the outer peripheral surface. The welded taper portion is formed so as to protrude from the outer peripheral surface. Then, with the rectifier inserted into the outflow port, the welding tapered portion of the rectifier and the welding tapered portion abutting portion of the outflow port are welded by laser light. Resin deformation due to welding between the rectifier and the outflow port can be absorbed by the gap between the outer circumference of the rectifier and the inner circumference of the outflow port. In particular, since the tip of the outflow port is closed by the flange, the molten resin does not flow out.

The second purge valve of the present disclosure forms a rectifying space having a constant passage cross-sectional area at a portion on the inner circumference of the outflow port between the valve seat passage and one end of the rectifier. Therefore, the evaporated fuel and air do not flow directly from the valve seat passage into the rectifying passage of the rectifier. After rectifying in this rectifying space, the evaporated fuel and air flow into the rectifying passage of the rectifier, so that the effect of reducing abnormal noise of the rectifier can be enhanced. Further, since the passage cross-sectional area of the rectifying space is the same as the passage cross-sectional area of the valve seat passage at the position where it communicates with the outflow port, the vaporized fuel and air between the valve seat passage and the rectifying space The flow can be smoothed.

In the third aspect of the present disclosure, the cross-sectional area of the valve seat passage at the throttle portion and the total cross-sectional area of the rectifying passage of the rectifier are substantially the same. While suppressing the influence of the increase in the flow resistance of evaporated fuel and air due to the rectifying passage, the effect of reducing abnormal noise is obtained by the rectifying passage.

In the fourth aspect of the present disclosure, a hose that guides evaporated fuel and air to the intake passage side is arranged on the outer periphery of the outflow port, and a locking shoulder portion that prevents the hose from coming off is formed at the tip of the outflow port. .. Then, the welding taper portion of the rectifier is positioned at a position where the locking shoulder portion is removed. Therefore, welding by laser light is not hindered by the locking shoulder portion.

Fifth of the present disclosure, the welded taper portion is intermittently formed on the outer periphery of the rectifier in the circumferential direction. When absorbing the resin deformation due to welding between the rectifier and the outflow port in the gap between the outer circumference of the rectifier and the inner circumference of the outflow port, the entire circumference around the welding taper portion can be used. Moreover, the pressing force when inserting the rectifier into the outflow port does not become excessive.

FIG. 1 is a diagram illustrating a usage state of the purge valve. FIG. 2 is a cross-sectional view of the purge valve. FIG. 3 is a front view of the rectifier shown in FIG. FIG. 4 is a side view of the rectifier shown in FIG. FIG. 5 is a cross-sectional view showing the coupling state of the outflow port and the hose. FIG. 6 is a cross-sectional view showing laser welding. FIG. 7 is a side view showing another example of the rectifier. FIG. 8 is a side view showing still another example of the rectifier.

FIG. 1 shows the usage state of the purge valve. The hydrocarbon gas evaporated in the fuel tank 100 (hereinafter referred to as evaporated fuel) is adsorbed on the canister 110. As the amount of suction on the canister 110 increases, the purge valve 200 opens the purge passage 120. Since the purge passage 120 communicates the canister 110 with the intake passage 140 downstream of the throttle valve 135 of the engine 130, when the purge valve 200 is opened, the evaporated fuel is sucked into the intake passage 140 together with the air taken in from the atmosphere valve 112. NS. Reference numeral 137 indicates an air filter, and 138 indicates an intake manifold. Also, the atmospheric valve 112 is normally open.

As shown in FIG. 2, in the purge valve 200, a coil 202 is formed by winding a copper wire many times around a bobbin 201 made of a resin material. A yoke 203 made of a magnetic material is arranged on the outer circumference of the coil 202, and a stator 204 made of a magnetic material is also arranged on the inner circumference of the coil 202. A plunger 205 made of a magnetic material is arranged on the inner circumference of the coil 202 so as to face the stator 204 via a magnetic gap. The plunger 205 is urged by a compression spring 206 in a direction away from the stator 204. Further, a valve body 207 made of a rubber material is insert-molded in the plunger 205. Reference numeral 208 denotes a guide member for the compression spring 206, which is fixed to the inner circumference of the stator 204.

The bobbin 201, coil 202, yoke 203, stator 204 and guide member 208 are insert-molded into the valve body 210 as a whole. The bulb body 210 is a resin material that absorbs laser light, and polybutylene terephthalate PBT, polyamide PA66, or the like is used. A connector 211 is formed on the valve body 210, and a pair of terminals 212 that are electrically connected to the coil 202 are exposed to the connector 211. Further, the valve body 210 is formed in a circular tubular shape with an inflow port 213 into which evaporative fuel or air from the canister 110 flows in. A hose constituting the purge passage 120 is attached to the outer periphery of the inflow port 213.

Reference numeral 220 denotes a rectifier body, which constitutes the valve chamber 221 together with the valve body 210. The rectifier body 220 is also made of a resin material such as polybutylene terephthalate PBT or polyamide PA66, but transmits laser light.

A cylindrical valve seat member 222 is formed in the rectifier body 220 toward the valve chamber 221. The tip of the valve seat member 222 forms a tapered valve seat 223. The valve body 207 described above is pressed against the valve seat 223 by a compression spring 206 via a plunger 205. Since the valve body 207 is made of a rubber material and the valve seat 223 has a tapered shape, even if the valve body 207 is slightly tilted by the compression spring 206, its peripheral surface appropriately abuts on the valve seat 223, which is sufficient. Sealing performance can be ensured.

A valve seat passage 224 is formed on the inner circumference of the valve seat member 222, and the passage cross-sectional area of the valve seat passage 224 is minimized at the valve seat 223 portion to form the throttle portion 209. Then, the passage cross-sectional area gradually expands from the throttle portion 209. Around the throttle portion 209, it has a circular cross section with a diameter of about 4 to 5 mm, and at the most widened position, it has a circular cross section with a diameter of less than 9 mm. In the present disclosure, the inclination angle of the valve seat passage 224 is about 10 degrees.

A cylindrical outflow port 230 is formed so as to project from the rectifier body 220. The length of the outflow port 230 is about 20 mm, and the wall thickness is about 2 mm. A rectifying space 231 is formed inside the outflow port 230, and the cross section of the passage is the same as the most widened portion of the valve seat passage 224 and has a circular cross section with a diameter of less than 9 mm. Therefore, the rectifying space 231 and the valve seat passage 224 are continuous without any change in the passage cross-sectional area and the passage cross-sectional shape.

A columnar rectifier 240 is arranged at the tip of the outflow port 230. The rectifier 240 is also made of a resin material such as polybutylene terephthalate PBT or polyamide PA66, and absorbs laser light. The length of the rectifier 240 is about 10 millimeters. That is, the rectifier 240 is about half the length of the outflow port 230, and as a result, the length of the rectifier space 231 is also about 10 mm. The outer diameter of the rectifier 240 is smaller than the inner diameter of the outflow port 230, and a gap of about 0.15 to 0.2 mm is formed between the rectifier 240 and the outflow port 230.

As shown in FIG. 3, one end of the rectifier 240 is formed with an insertion taper portion 241 that serves as a guide when the rectifier 240 is inserted into the outflow port 230. The outer diameter of the insertion taper portion 241 is smaller than the inner diameter of the outflow port 230, and the insertion taper portion 241 does not abut on the inner circumference of the outflow port 230 in the inserted state. The width of the insertion taper portion 241 is about 1 mm, and a cylindrical guide portion 2411 having a width of about 1 mm is also formed at the rear end (left side in FIG. 3).

A flange portion 242 is formed at the other end of the rectifier 240 so as to project at a right angle in the radial direction. When the rectifier 240 is inserted into the outflow port 230, the flange portion 242 comes into contact with the tip of the outflow port 230 to perform axial alignment. The radial width of the flange portion 242 is smaller than the outer diameter of the outflow port 230, and the flange portion 242 does not interfere with the insertion of the hose 260, which will be described later.

A welding taper portion 243 that welds to the outflow port 230 is formed so as to protrude from the intermediate portion of the rectifier 240. The welding taper portion 243 has a triangular shape composed of a tapered surface 2431 having an inclination angle of about 30 degrees and a slope 2432 having an inclination angle of about 60 degrees continuous with the tapered surface 2431, and has a height of about 0.3 mm. .. As a result of the height of the welding taper portion 243 being larger than the gap between the rectifier 240 and the outflow port 230, when the rectifier 240 is inserted into the outflow port 230, of the top 2433 and the outflow port 230 of the welding taper portion 243, The portion that the top 2433 comes into contact with is elastically deformed.

A plurality of welded taper portions 243 are formed at equal intervals in the circumferential direction. In the present disclosure, the welding taper portions 243 are formed at six locations. Therefore, each welding taper portion 243 is independently formed so as to project from the outer periphery of the rectifier 240.

As shown in FIG. 4, a plurality of rectifier passages 245 are formed in the rectifier 240. In the present disclosure, one rectifying passage 245 is formed on the central axis, and six rectifying passages 245 are equally spaced in the circumferential direction. Each of the rectifying passages 245 has a circular cross section with a diameter of about 2 mm, and is formed linearly in the axial direction.

As shown in FIG. 5, a hose 260 forming a purge passage 120 is connected to the outer periphery of the outflow port 230. A locking shoulder portion 233 for preventing the hose 260 from coming off is formed on the outer periphery of the tip portion of the outflow port 230.

Next, the procedure for assembling the purge valve 200 having the above configuration will be described. First, the coil 202 is wound around the outer circumference of the bobbin 201, and the electromagnetic portion is assembled together with the yoke 203, the stator 204, and the like. In that state, the coil 202 is electrically connected to the pair of terminals 212, and is insert-molded into the valve body 210 together with the electromagnetic part and the terminals 212.

Further, the rectifier 240 is inserted from the tip side of the outflow port 230 of the rectifier body 220. At that time, the insertion taper portion 241 engages with the tip of the outflow port 230 to guide the insertion. Next, the welding taper portion 243 comes into contact with the tip of the outflow port 230, and the top of the welding taper portion 243 and the inner circumference of the outflow port 230 are elastically deformed. Here, since the welding taper portion 243 is formed intermittently over the entire circumference, the pressing force required for elastic deformation is not excessive. The rectifier 240 is inserted until the flange portion 242 abuts on the tip of the outflow port 230, and the rectifier 240 is positioned by the abutting of the flange portion 242.

Since the position of the welding taper portion 243 is accurately determined by positioning, as shown in FIG. 6, laser light 249 is applied to the welding taper portion 243 to irradiate the welding taper portion 243 and the outflow port 230 in contact with the welding taper portion 243. Melt and laser weld. The site indicated by reference numeral 247 in FIG. 5 is a welding site. At the time of laser welding, the top 2433 of the welding taper portion 243 melts and flows into the gap between the rectifier 240 and the outflow port 230, but the guide portion 2411 can prevent it from flowing out into the rectifying space 231. Further, since the flange portion 242 is in contact with the tip of the outflow port 230, it is possible to prevent the flange portion 242 from flowing out to the outside. Moreover, since the welding taper portion 243 is separated in the circumferential direction, the amount of the welded taper portion 243 is limited even if it is melted. Moreover, since it spreads all around the welded taper portion 243, the outflow to the rectified space 231 is surely suppressed.

Since the laser light 249 of the laser welding focuses on the top 2433 of the welding taper portion 243, even if the laser light 249 hits the portion where the welding taper portion 243 is not formed on the outer periphery of the rectifier 240. It does not melt the part.

Further, in the present disclosure, the welding taper portion 243 is located at a portion of the outflow port 230 where the locking shoulder portion 233 is removed. Since the wall thickness of the outflow port 230 changes in the locking shoulder portion 233, if the portion is irradiated with the laser beam 249, the laser beam 249 reaching the welding taper portion 243 may also change. be. However, in the present disclosure, since the welding taper portion 243 is arranged at a portion where the wall thickness of the outflow port 230 is constant, the laser beam 249 reaching the welding taper portion 243 can be kept constant.

Next, the guide member 208 of the compression spring 206, the compression spring 206, and the plunger 205 in which the valve body 207 is insert-molded are arranged on the valve body 210 in which the electromagnetic portion is insert-molded. In that state, the rectifier body 220 is assembled to the valve body 210 so that the valve body 207 comes into contact with the valve seat 223. After assembly, the contact surface flange 220a of the rectifier body 220 and the contact surface flange 210a of the valve body 210 are laser welded.

Next, the operation of the purge valve 200 of the present disclosure will be described. When the amount of evaporated fuel adhering to the canister 110 is small, the purge passage 120 is closed by the purge valve 200. That is, the coil 202 is not energized, and the plunger 205 receives an urging force in the direction away from the stator 204 by the compression spring 206. By this urging force, the valve body 207 is pressed against the valve seat 223, and the valve seat passage 224 is closed.

When the amount of fuel evaporated in the canister 110 increases and it is necessary to open the purge passage 120, the purge valve 200 opens the purge passage 120. Here, since the atmospheric valve 112 is normally open, air is introduced into the canister.

At this time, the coil 202 of the purge valve 200 is energized. By energization, a magnetic circuit of the coil 202 is formed in the stator 204, the yoke 203, and the plunger 205, and an attractive force is generated in the magnetic gap between the stator 204 and the plunger 205. This suction force overcomes the urging force of the compression spring 206 to move the plunger 205 toward the stator 204, and the valve body 207 separates from the valve seat 223 with the movement. The valve body 207 is separated from the valve seat 223 by a maximum of 1 mm.

Since the atmospheric valve 112 is open, the canister 110 side has an atmospheric pressure, while the intake passage 140 is downstream of the throttle valve 135, so that the pressure is negative. Therefore, due to the pressure difference, the evaporated fuel and air flow from the canister 110 to the intake passage 140 via the purge passage 120.

More specifically, the evaporated fuel and air that have flowed in from the inflow port 213 flow into the valve chamber 221 and flow into the throttle portion 209 of the valve seat passage 224 from the entire circumference of the valve seat 223 of the valve seat member 222. In particular, when the throttle valve 135 is closed in the idling state of the engine, the pressure difference due to the negative pressure is large, so that the maximum amount of evaporated fuel and air of about 120 liters per minute flows into the valve seat passage 224.

Since the valve seat passage 224 has a small cross-sectional area of the valve seat 223 portion, the pressure receiving area of the valve body 207 is also small, and the valve body 207 is easily moved by the exciting force of the coil 202. Moreover, the sealing surface between the valve body 207 and the valve seat 223 is made smaller to improve the sealing performance.

In the valve seat passage 224, the passage cross-sectional area is gradually increased downstream of the throttle portion 209 to gradually reduce the flow velocities of the evaporated fuel and air. Further, the flow of the evaporated fuel and the air is made smooth by avoiding a sudden change in the passage cross-sectional area in the valve seat passage 224. However, it is not possible to prevent the generation of a vortex flow due to a change in the cross-sectional area of the passage, and a vortex flow is generated downstream of the throttle portion 209.

In the present disclosure, a rectifying space 231 is formed in the outflow port 230 continuously to the valve seat passage 224. The rectifying space 231 stabilizes the vortex flow generated in the valve seat passage 224. In that state, the evaporated fuel and air flow into the rectifier passage 245 of the rectifier 240. In other words, the rectifying space 231 is located upstream of the rectifying passage 245, and suppresses the vortex flow generated in the valve seat passage 224 in cooperation with the rectifying passage 245. Thereby, it is possible to suppress the generation of abnormal noise caused by the vortex flow of the evaporated fuel and the air.

In the present disclosure, the passage cross-sectional area of the valve seat 223 portion (throttle portion 209) of the valve seat passage 224 and the total passage cross-sectional area of the rectifier passage 245 of the rectifier 240 are substantially the same. Therefore, there is no significant change between the flow velocities of the evaporated fuel and air at the valve seat 223 portion (throttle portion 209) and the flow velocities at the rectifier 240.

Although the above is a desirable aspect of the present disclosure, the present disclosure can be changed in various ways. For example, in the above disclosure, the cross-sectional shape of the rectifying passage 245 is circular, but other shapes may be used. Further, the number of rectifying passages 245 may be less than 7, or conversely, may be increased.

FIG. 7 is an example in which six rectifying passages 245 are provided in a fan shape, and FIG. 8 is an example in which four rectifying passages 245 are provided in a square shape. In this way, even if the number and shape of the rectifying passages 245 are changed, it is possible to obtain the effect of reducing the abnormal noise of the rectifier 240 by reducing the passage cross-sectional area of the rectifying passages 245.

Further, in the above disclosure, the total cross-sectional area of the rectifying passage 245 is substantially the same as the passage cross-sectional area of the valve seat 223 portion, but the total cross-sectional area may be larger than the passage cross-sectional area of the valve seat 223 portion. It is desirable that the passage cross-sectional area is substantially the same, but even if the passage cross-sectional area is different, the generation of vortex flow in the valve seat passage 224 is suppressed by restricting the flow of evaporated fuel and air by the rectifying passage 245. It is possible.

Further, in the above disclosure, a rectifying space 231 having a length similar to that of the rectifier 240 is formed between the rectifier 240 and the valve seat passage 224, but even if the length of the rectifying space 231 is made longer, the reverse is true. May be shortened to. The rectifying space 231 also has a desirable volume, but even if the volume is changed, it is possible to suppress the generation of vortex flow in the valve seat passage 224. In an extreme case, the valve seat passage 224 and the rectifying passage 245 may be continuous.

Further, in the above disclosure, the welding taper portion 243 is formed intermittently in the circumferential direction, but it is also possible to form the welding taper portion 243 over the entire circumference in the circumferential direction. Even if the resin is formed over the entire circumference, the melted resin can be prevented from flowing out into the rectifying space 231 by the guide 2411, and can be prevented from flowing out by the flange portion 242. However, when the rectifier 240 is formed over the entire circumference, the pressing force when the rectifier 240 is inserted into the outflow port 230 becomes large, so it is necessary to devise the height and shape of the welding taper portion 243.

It is also possible to abolish the guide 2411. Since the insertion of the rectifier 240 is guided by the insertion taper portion 241 and the insertion taper portion 241 is also formed to protrude on the outer peripheral surface, the flow-out of the melted resin can be prevented by the insertion taper portion 241 as well.

200 ... Purge valve 202 ... Coil 204 ... Stator 205 ... Plunger 207 ... Valve body 210 ... Valve body 220 ... Rectifier body 222 ... Valve seat member 223 ... Valve Seat 224 ... Valve seat passage 230 ... Outflow port 231 ... Rectifier space 240 ... Rectifier 241 ... Insertion taper portion 242 ... Flange portion 243 ... Welding taper portion

Claims (5)

A coil that excites when energized and
A magnetic material stator placed in the magnetic circuit when the coil is energized,
A plunger placed opposite to the stator in the magnetic circuit when the coil is energized via a magnetic gap,
The valve body that moves with this plunger,
An inflow port for inflowing evaporative fuel and air from the canister,
The valve chamber that communicates with this inflow port,
A cylindrical valve seat member arranged in this valve chamber and
A valve seat located at the tip of the valve seat member and with which the valve body abuts,
A compression spring that presses the valve body toward the valve seat side,
A valve seat passage formed inside the valve seat member and
An outflow port formed of a cylindrical laser light transmitting resin that communicates with the valve seat passage to allow evaporated fuel and air to flow out to the intake passage side.
It is formed of a cylindrical laser light absorbing resin, is inserted from the tip of the outflow port, and is provided with a rectifier having a rectifying passage inside.
In the valve seat passage, a throttle portion is formed at the valve seat portion with the minimum passage cross-sectional area, and the passage area is sequentially increased from the throttle portion toward the outflow port.
The outflow port communicates at a position where the passage cross-sectional area of the valve seat passage is maximum, and the passage cross-sectional area is the same as the maximum passage cross-sectional area of the valve seat passage.
The total passage cross-sectional area of the rectifying passage is smaller than the passage cross-sectional area of the outflow port.
The rectifier has an insertion taper portion protruding from the outer peripheral surface at one end thereof, a flange portion protruding from the outer peripheral surface at the other end and a flange portion abutting with the tip end portion of the outflow port, and a welding tapered portion protruding from the outer peripheral surface. Protruding from the outer peripheral surface,
A purge valve characterized in that, in a state where the rectifier is inserted into the outflow port, the welding tapered portion of the rectifier and the welding tapered portion abutting portion of the outflow port are laser-welded. The purge valve according to claim 1, wherein a rectifying space having a constant passage cross-sectional area is formed between the valve seat passage and one end of the rectifier on the inner circumference of the outflow port. The purge valve according to claim 1 or 2, wherein the passage cross-sectional area of the valve seat passage at the position of the valve seat and the total passage cross-sectional area of the rectifying passage of the rectifier are substantially the same. .. A hose that guides the evaporated fuel and air to the intake passage side is arranged on the outer periphery of the outflow port.
A locking shoulder portion for preventing the hose from coming off is formed at the tip portion of the outflow port.
The purge valve according to any one of claims 1 to 3, wherein the welding taper portion of the rectifier is located at a position where the locking shoulder portion is removed. The purge valve according to any one of claims 1 to 4, wherein the welding taper portion is formed so as to intermittently project from the outer periphery of the rectifier in the circumferential direction.

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