JP2017067104A - Valve element driving mechanism and flow rate control valve including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem on a poor degree of freedom in spray layout, of a structure in which a piezoelectric element is expanded by application of voltage, and a fuel is injected by pushing a valve element, but as a valve tip generally has the conical shape so that the produced spray is umbrella-shaped spray, in comparison with a flow rate control valve which sprays a fuel from multiple injection holes by pushing up a valve element by energization.SOLUTION: A valve element driving mechanism includes a push-up portion for pushing up a valve element, a support portion kept into contact with the push-up portion for supporting the same at an outer peripheral side with respect to an inner peripheral-side end portion of the push-up portion, and an operation portion kept into contact with the push-up portion at an outer peripheral side with respect to the contact portion of the support portion and the push-up portion for moving the push-up portion downward. The push-up portion moved downward by the operation portion is brought into contact with the valve element at an inner peripheral side with respect to the contact portion, thus the valve element is pushed up.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a valve body drive mechanism and a flow control valve including the valve body drive mechanism, and more particularly to a drive element operation direction deflecting member.

  In Patent Document 1, when the energization is started, the extension of the piezoelectric element is directly transmitted to the valve body, and when the valve body is pushed, the tip of the valve body is separated from the valve seat, thereby forming a fuel flow path from which fuel is supplied. A flow control valve having a structure in which, after injection and energization, the valve body is pulled back by the force of the spring provided in the valve body, abuts against the valve seat, and the fuel flow path is closed to terminate the fuel injection. Have been described.

JP 2002-31010 A

  Since the piezoelectric element has a structure that expands when a voltage is applied, it has a structure in which fuel is injected by pushing the valve body. The tip of the valve body is generally conical, and the generated spray is an umbrella spray. Compared with a flow control valve that pulls up the valve body by energization and sprays fuel from the multi-holes, the degree of freedom in spray layout is small. An object of the present invention is to operate so as to form a fuel passage by closing a fuel passage by making contact with the valve seat on the outer peripheral portion of the nozzle tip, contacting the valve seat, and leaving the valve seat. In the flow control valve provided with the said valve body, it is providing the flow control valve which enabled it to make it eject from a multi-injection hole with a simple mechanism.

  In order to solve the above-mentioned problems, the present invention provides: “a push-up portion that pushes up the valve body, a support portion that contacts and supports the push-up portion on an outer peripheral side of an inner peripheral side end portion of the push-up portion; And an operation part that moves the push-up part downward in contact with the push-up part on the outer peripheral side of the contact part between the push-up part and the push-up part. The valve body is pushed up by contacting with the valve body on the inner peripheral side of the contact portion.

  According to the above solution, the valve seat that contacts the valve body at the outer periphery of the nozzle tip, the fuel passage is closed by contacting the valve seat, and the fuel passage is formed by moving away from the valve seat. In the flow control valve including the valve body, the flow control valve that can be ejected from the multi-holes with a simple mechanism can be provided.

1 is an overall view of a fuel injection valve according to the present embodiment. The cross-sectional enlarged view of the valve body drive mechanism of a present Example is shown. The three-dimensional shape figure of the valve body drive mechanism of a present Example is shown. It is a figure for demonstrating operation | movement of the valve body drive mechanism of a present Example. The figure which used the piezoelectric element as a drive element is shown.

  Embodiments of a fuel injection valve in which the structure of the present invention is often used will be described below with reference to the accompanying drawings.

  FIG. 1 shows an overall view of a fuel injection valve according to the present embodiment. FIG. 1A shows a state in which the fuel injection valve 1 is closed, and FIG. The enlarged view when it is in a valve open state is shown.

  Fuel is supplied from a fuel supply port 8 above the fuel injection valve. The fuel flows through the gap in the double circular tube and reaches the valve seat through the gap between the nozzle 3 and the valve body 2. The driving element 6 uses an element that expands in proportion to voltage or current. Further, a valve element drive mechanism 12 is provided at the lower end of the drive element 6 and has a function of converting the operation of the drive element 6 extending in the downstream direction into the upstream direction. As will be described later, according to the present embodiment, the valve element drive mechanism 12 and the end of the valve element 2 are in contact with each other, and the valve element 2 can be lifted upstream. The valve seat 1 is formed on the outer peripheral portion of the nozzle 3 at the tip, and the valve seat 1 is provided at the tip of the nozzle 3. The valve seat 1 is joined to the tip of the nozzle 3 by welding or the like. When the drive element 6 operates, the contacting valve body 2 is pushed upward, the valve body 2 is separated from the valve seat 1, the seat portion fuel flow path 10 a is formed, and the valve seat 1 is opened. Fuel is injected from the injection hole 11. When the energization is completed, the valve body 2 and the valve seat 1 come into contact with each other by the force of the spring 4 provided on the valve body 2, and a gap generated thereby closes the seat portion fuel flow path 10 and the injection ends.

  As described in the background, the fuel injection valve having the drive element 6 and the piezoelectric element 17 (piezo element) generally has a structure in which fuel is injected by pushing the valve body 2. Therefore, from the viewpoint of strength and the like, the tip of the valve body generally takes a conical shape, and the generated spray is an umbrella spray. Compared with a flow control valve that is capable of pulling up the valve body 2 by energization that is currently being developed and allowing fuel to be ejected from a plurality of injection holes, there is a problem that the degree of freedom in spray layout is small.

  Therefore, in this embodiment, the valve body drive mechanism 12 is provided between the drive element 6 and the valve body 2 so that the valve body 2 can be pulled up while the drive element 6 is used. As shown in FIGS. 1A and 1B, the valve is opened when energized, and the valve is closed when de-energized. As a result, it is possible to obtain an effect that a plurality of fuel injection holes can be used. The structure and operating principle of the valve body drive mechanism will be described in detail later.

In FIG. 2, the cross-sectional enlarged view of the valve body drive mechanism 12 is shown. In addition, FIG. 3 shows a three-dimensional shape diagram of the valve body drive mechanism 12. The valve body drive mechanism 12 includes a rod 13, a drive element 6 and a plate-like member 14a, a ring-like member 14, a pedestal portion 15, a valve body cap portion 16, and a metal seal portion B 5b. Next, these operation mechanisms will be described. In the case of a flow control valve using the drive element 6, since the deterioration or corrosion occurs when the drive element 6 comes into contact with the fuel, a metal seal member is installed.
In this embodiment, the ring-shaped member 14 or the plate-shaped member 14a is called a push-up portion because it plays the role of pushing up the valve body 2. Moreover, the valve body drive mechanism 12 is provided with the support part (base part 15) which contacts and supports on the outer peripheral side rather than the inner peripheral side edge part of the pushing-up part (ring-shaped member 14, plate-shaped member 14a). The rod 13 has a push-up portion (ring-like member 14 and plate-like member 14a) and a contact portion 21 between the support portion (pedestal portion 15) and the push-up portion (ring-like member 14 and plate-like member 14a) on the outer peripheral side. In contact with each other, the push-up portion (ring-shaped member 14, plate-shaped member 14a) is moved downward. Therefore, in the present embodiment, the rod 13 is referred to as an operation unit. The push-up portion (ring-shaped member 14, plate-shaped member 14 a) moved downward by the operating portion (rod 13) pushes up the valve body 2 by contacting the valve body 2 on the inner peripheral side with respect to the contact portion 21.

  Contrary to the structure of the present embodiment, the operating portion (rod 13) includes a push-up portion (ring-like member 14, plate-like member 14a), a support portion (pedestal portion 15), and a push-up portion (ring-like member 14). Further, the contact portion 21 with the plate-like member 14a) may be contacted on the inner peripheral side and moved downward.

  The operation of the valve body drive mechanism 12 of this embodiment will be specifically described with reference to FIGS. The plate-like member 14 can pull up the valve body 2 to the upper part by the lever principle. A driving element 6 is provided in the upper part of the valve body driving mechanism 12, and when the driving element 6 is energized, the driving force is transmitted in the downstream direction. At this time, the support part (pedestal part 15), the action part (rod 13), and the push-up part (ring-like member 14, plate-like member 14a) of the plate-like member 14a operate by the action of the fulcrum, the force point, and the action point. Thus, the driving force transmitted in the downstream direction can be converted into the force in the upstream direction.

  Specifically, the push-up portion has a frame member (ring-shaped member 14) disposed at a position in contact with the operating portion (rod 13), and the driving force by the driving element 6 is applied to the frame member (ring-shaped member 14). The transmitting operation part is constituted by a plurality of rods 13 provided in the axial direction between the drive element 6 and the frame member (ring-shaped member 14). Further, the plurality of rods 13 are arranged with an equal interval in the circumferential direction. The plate-like member 14 a is attached to the inner peripheral side of the ring-like member 14, and the plurality of rods 13 urge the ring-like member 14 to move the plate-like member in the downstream direction.

  It is possible to provide a metal member that connects the frame member 23 and the plate-like member 14a (ring-like member 14) over the entire circumference instead of the plurality of rods 13, but the present embodiment can reduce the material. Become. Further, it is desirable that the plurality of rods 13 be arranged with at least three and equal intervals. This is because the force applied from the drive element 6 disposed on the upper part of the valve body drive mechanism 12 is equally applied to the valve body drive mechanism 12. In addition, when they are not evenly arranged, the valve body drive mechanism 12 can be inclined. It is preferable to avoid tilting because it can cause failure and damage to parts.

  According to the valve body drive mechanism 12 of the present embodiment, as described above, the plurality of rods 13 urge the ring-shaped member 14 and the plurality of plate-shaped members 14a, whereby the valve body 2 is upstream (or plural). The plate-like member 14 is provided with an equal interval. Further, like the rod 13 described above, it is desirable that a plurality of, more specifically three or more plate-like members 14a be arranged. This is also because there is a concern that the force of the driving element 6 transmitted from the upper part is biased and prevents the driving element 6 from being transmitted to the downstream part. It may be a cause of failure and damage of the member 14. The plate-like member 14 is desirably a metal from the viewpoint of strength.

  In the valve body drive mechanism 12, a flange portion is provided on the upper portion of the valve body 2, and the flange portion is in contact with an inner peripheral side end portion of the push-up portion (plate-like member 14a). In addition, a flange part points out the part which protrudes in the outer peripheral part of the cap part 16 of FIG. Moreover, although the flange part is formed in the cap part 16 provided in the upper end part of the valve body 2, you may make it form not only in this but in the upper part of the valve body 2. FIG. When this portion catches the plate-like member 14 described above, the valve body plays a role of being pushed up in the upstream direction.

  That is, in the flow control valve provided with the valve body driving mechanism 12 described above, the flange portion is provided at the upper portion of the valve body, and the valve body and the flange portion can be applied even when they are separate bodies. The valve body of the fuel injection valve using the drive element 6 is very long. Therefore, there is a problem that processing is difficult when the flange portion is installed on the upper portion of the valve body. Therefore, a fuel seal member B 5b separate from the valve body and a cap member 16 disposed on the metal seal member are provided on the valve body. By taking this configuration, the processing is simplified. In fact, simplification of assembly when assembling the flow control valve can also be expected. Further, the fuel seal member bracket B 5b need not be a metal as long as it can play a role of sealing the fuel, and other materials can be used.

  In this embodiment, the valve body driving mechanism 12 can be applied to any flow control valve. In the present embodiment, the fuel injection valve will be described as an example.

  In the valve body drive mechanism 12 described above, the push-up portion (plate-like member 14a) abuts the lower portion of the flange portion, and when the portion that contacts the lower portion of the flange portion serves as the action point and the portion that contacts the rod 13 serves as the force point, the push-up portion The valve body 2 is pushed up with the portion provided at the lower part of the (plate-like member 14a) as a fulcrum. Thus, the push-up portion (ring-shaped member 14, plate-shaped member 14a) can push up the valve body 2 using the lever principle. This operation will be described with reference to FIG. FIG. 4A shows a state before the drive element 6 is energized. Therefore, the above-described plate-like member 14 also exists on a plane without being pushed down. Subsequently, the valve body drive mechanism 12 at the time when energization to the drive element 6 is started is shown in FIG. As can be seen from this figure, the driving force generated from the driving element 6 is transmitted to the plate-like member 14 through the operating portion. Thereby, the outer peripheral side end of the plate-like member 14 is pushed down in the downstream direction. As a result, the contact portion 21 acts as a fulcrum and the push-down portion acts as an action point, and pushes up the valve body 2 in the upstream direction. FIG. 4 (3) shows a state where the plate-like member 14 is pushed down to the extent that it contacts the pedestal. As apparent from this figure, the valve body 2 is pushed up by pushing down the operating portion (rod 13). In summary, even when the driving force is shown in the downstream direction after the drive element 6 is energized, the valve element 2 itself can transmit a force in the opposite direction to the driving force via the valve element drive mechanism 12. it can.

  The fuel injection valve provided with the valve body drive mechanism 12 has a plurality of injection holes. Generally, in a fuel injection valve that performs fuel injection using the drive element 6, the drive element 6 has a structure that expands when a voltage is applied. Therefore, a structure in which fuel is injected by pushing the valve body 2. It becomes. Therefore, in order to solve the problem of strength, the tip of the valve body 2 is generally conical, and the generated spray is an umbrella spray. However, compared with a fuel injection valve that pulls up the valve body 2 by energization and sprays fuel from a plurality of injection holes, the degree of freedom of spray layout is very low. In order to efficiently spray the fuel injection valve, it is preferable to improve the spray layout even when the drive element 6 is used.

  Therefore, in this embodiment, by reversing the drive direction of the drive element 6 using the valve body drive mechanism 12, it becomes possible to inject fuel in the same manner as the fuel injection valve that drives the valve body 2 by energization. . Therefore, even the fuel injection valve of this embodiment in which fuel is injected by the drive element 6 can have a plurality of injection holes. As a result, even when the drive element 6 is used, it is possible to obtain a specific effect that improvement in spray layout can be expected.

  In the first embodiment, an example in which the drive element 6 is used as a drive unit has been introduced. However, in this embodiment, a piezoelectric element 17 is used as the drive element 6 as shown in FIG. Since the operation period of the piezoelectric element 17 is much faster than that of the other driving elements 6, the piezoelectric element 17 can be driven with a low injection pulse, and exhibits a remarkable effect that fuel can be stably injected with a small amount. .

However, when fuel is injected, the fuel injection valve itself is also in a high temperature state. In some cases, the linear expansion coefficient of a member constituting the piezoelectric element 17 is smaller than that of a metal part (for example, stainless steel) constituting the flow control valve. At this time, when the temperature rises, the metal constituting the flow control valve greatly expands, but the drive element 6 does not extend beyond the metal, and as a result, the distance to push down the valve body 2 is shortened, and the fuel is reduced. This causes a problem that the seal cannot be sealed and continues to flow out.
Therefore, the fuel injection valve provided with the valve body drive mechanism 12 of the present embodiment is characterized in that a damper 7 is provided above the drive element 6. The damper 7 is composed of a cylinder and a plunger, and additionally oil sealed in a gap between the cylinder and the plunger. Since oil is sealed in the gap between the cylinder and the plunger, when the temperature rises, the oil expands and the cylinder extends. By extending the cylinder in this manner, a gap between the valve seat and the valve body 2 is not generated. For this reason, the elongation amount by the drive element 6 can be made larger than the elongation amount of the metal which comprises a fuel injection valve. In the case of the present embodiment, since the valve body driving mechanism 12 is provided, the interval until the driving force is applied to the valve body 2 is increased, and thus the amount of elongation by the driving element 6 is shortened to some extent. Therefore, the damper 7 plays an important role.

  Note that the piezoelectric element 17 can be installed in a liquid if it has a waterproof and sealed structure or has fuel resistance.

  This is the end of the description of the examples, but the present invention is not limited to the above-described embodiment, and can be widely modified and implemented. In the present embodiment, the fuel control valve using the drive element has been mainly described. However, the drive control element may be applied to a magnetostrictive element or a piezoelectric element, or may be applied to a flow control valve other than the fuel control valve. May be. Also, the method of arranging the fuel injection valve is not limited to the example in the above embodiment.

DESCRIPTION OF SYMBOLS 1 Valve seat 2 Valve body 3 Nozzle 4 Spring 5 Metal seal member 5a Metal seal member metal fitting A
5b Metallic seal member bracket B
6 Drive element 7 Damper 8 Fuel supply port 9 Voltage input terminal 10 Seat portion 10a Seat portion fuel flow path 11 Injection hole 12 Valve element drive mechanism 13 Rod 14 Frame member 14a Plate member 15 Base 16 Metal seal member upper metal fitting cap 17 Piezoelectric Element 20 Push-up part 21 Support part 22 Operation part

Claims (9)

A push-up unit that pushes up the valve body;
A support portion that contacts and supports the push-up portion on the outer peripheral side of the inner peripheral side end of the push-up portion;
An operation portion that contacts the push-up portion on the outer peripheral side of the contact portion between the support portion and the push-up portion and moves the push-up portion downward;
The valve body drive mechanism characterized in that the push-up portion moved downward by the operating portion pushes up the valve body by contacting the valve body on the inner peripheral side of the contact portion. In the valve body drive mechanism according to claim 1,
The push-up portion has a frame member disposed at a position in contact with the operating portion,
The operating portion that transmits the driving force by the driving element to the frame member is constituted by a plurality of rods provided in the axial direction between the driving element and the frame member,
The valve body driving mechanism, wherein the plurality of rods are arranged at equal intervals in the circumferential direction. In the valve body drive mechanism according to claim 1 or 2,
The push-up part, the support part, and the action part exist on the same plate-shaped member,
A plurality of the plate-like members are provided,
The valve member driving mechanism, wherein the plate-like members are arranged with an equal interval. In the valve body drive mechanism in any one of Claim 1 to 3,
A valve body drive mechanism comprising a flange portion provided on an upper portion of the valve body, the flange portion being in contact with the inner peripheral side end portion of the plate-like member. In the valve body drive mechanism according to claim 4,
The push-up portion is in contact with the lower portion of the flange portion, and the push-up portion in contact with the lower portion of the flange portion is a point of action.
When the action part that the frame member contacts is a power point,
A valve body drive mechanism that pushes up the valve body by using a contact portion provided at a lower portion of the push-up portion as a fulcrum. In the flow control valve provided with the valve body drive mechanism according to claim 5,
The flange portion is provided on an upper portion of the valve body, and the valve body and the flange portion are separate bodies. In the flow control valve provided with the valve body drive mechanism according to any one of claims 1 to 6,
The flow rate control valve, wherein the drive element is a piezoelectric element. In the flow control valve provided with the valve body drive mechanism according to claim 1,
The flow rate control valve has a plurality of injection holes. In the flow control valve provided with the valve body drive mechanism according to claim 1,
A flow control valve characterized in that a damper is provided above the drive element.

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