Fuel injection pump control device and engine

Abstract

To provide a control device for a fuel injection pump that can reduce wear of components, and to provide an engine.SOLUTION: A control device 30 includes: a solenoid 31; and a link mechanism 32 for connecting the solenoid 31 to a stop lever 21 of a fuel injection pump 20. The link mechanism 32 includes a slide pin 321 connected to a movable shaft 311 of the solenoid 31 and slidably moving integrally with the movable shaft 311. The control device 30 further includes a support pin 331 for supporting the slide movement of the slide pin 321 from below.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a control device for a fuel injection pump and an engine equipped with the same.

Background Art

[0002] Patent Document 1 discloses a technique for controlling fuel injection in a fuel injection pump of an engine by moving a lever (fuel injection control lever) via a link mechanism with an actuator (such as a solenoid). In such a technique, the layout of the actuator and the fuel injection pump and the link mechanism connecting them are designed for each engine model.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a configuration including an actuator and a link mechanism is used as a control device for a fuel injection pump, there is a concern that component wear may occur in the control device due to repeated operations, resulting in the inability to accurately control fuel injection.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a control device for a fuel injection pump and an engine capable of reducing component wear.

Means for Solving the Problems

[0006] To solve the above problems, a control device according to a first aspect of the present disclosure is a control device for controlling a fuel injection pump provided in an engine, comprising a solenoid and a link mechanism connecting the solenoid and a fuel injection control lever of the fuel injection pump, wherein the link mechanism has a sliding member connected to the solenoid, and further comprises a support member that supports the sliding member from below.

[0007] With the above configuration, the support member supports the sliding member from below, preventing the movable shaft of the solenoid from tilting downward due to the weight of the sliding member. When the movable shaft of the solenoid tilts, wear of the internal parts of the solenoid is more likely to occur, so preventing this tilt can suppress wear of the solenoid's parts.

[0008] Furthermore, in the control device described above, the link mechanism can be configured to include a rotating member that rotates in conjunction with the sliding movement of the slide member, and a connecting member that slides integrally with the slide member and is inserted through an elongated hole provided in the rotating member, thereby converting the sliding displacement of the slide member into the rotational displacement of the rotating member.

[0009] Furthermore, in the control device described above, the elongated hole can be configured as a bent elongated hole in which the longitudinal axis is bent midway.

[0010] With the above configuration, at both ends of the sliding range of the sliding member, the tangent at the point of contact between the inner wall of the elongated hole and the connecting member can be made perpendicular to the sliding direction of the sliding member, thereby preventing the connecting member from moving along the inner wall of the elongated hole and tilting the movable axis of the solenoid. When the movable axis of the solenoid is tilted, wear of parts inside the solenoid is more likely to occur, so by preventing this tilt, wear of the solenoid's parts can be suppressed.

[0011] Furthermore, the control device may be configured to include a contact member that contacts the slide member from above.

[0012] According to the above configuration, the sliding member contacts the contact member, preventing the sliding member from lifting up and preventing the tilting of the movable shaft of the solenoid connected to the sliding member. By preventing this tilting, wear on the solenoid's components can be suppressed.

[0013] Furthermore, an engine according to a second aspect of the present disclosure is an engine comprising a fuel injection pump and a control device for controlling the fuel injection pump, wherein the control device is the control device described above and is attached to the engine via a bracket of the engine. [Effects of the Invention]

[0014] The fuel injection pump control device and engine of this disclosure have the effect of preventing the movable shaft of the solenoid from tilting downward due to the weight of the sliding member by having a support member support the sliding movement of the sliding member from below, thereby suppressing wear of the solenoid components caused by this tilt. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing the appearance of an engine to which the control device of this disclosure is applied. [Figure 2] This is a perspective view of the fuel injection pump from the rear side, with the fuel injection pump and control unit removed. [Figure 3] This is a perspective view of the control device. [Figure 4] This is a plan view showing the connection mechanism between the slide pin and the first and second link plates via a connecting shaft. [Figure 5] This is a plan view showing the state of the slide pin and connecting shaft when the solenoid is energized. [Figure 6] This is an enlarged schematic diagram of the area around a slide pin to illustrate the issue of component wear in a control device, showing the state of the solenoid when it is not energized. [Figure 7]It is an enlarged schematic view near a slide pin for explaining the problem of component wear in the control device, and shows the state when the solenoid is energized. [Figure 8] It is an enlarged schematic view near a slide pin in the control device of Embodiment 1, and shows the state when the solenoid is not energized. [Figure 9] It is an enlarged schematic view near a slide pin in the control device of Embodiment 1, and shows the state when the solenoid is energized. [Figure 10] It is an enlarged schematic view near a slide pin for explaining the problem of component wear in the control device, and shows the state when the solenoid is energized. [Figure 11] It is an enlarged schematic view near a slide pin in the control device of Embodiment 2, and shows the state when the solenoid is not energized. [Figure 12] It is an enlarged schematic view near a slide pin in the control device of Embodiment 2, and shows the state when the solenoid is energized. [Figure 13] It is an enlarged schematic view near a slide pin in the control device of Embodiment 3, and shows the state when the solenoid is not energized. [Figure 14] It is an enlarged schematic view near a slide pin in the control device of Embodiment 3, and shows the state when the solenoid is energized.

Mode for Carrying Out the Invention

[0016] 〔Embodiment 1〕 Hereinafter, embodiments of the control device of the present disclosure will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of an engine 10 to which the control device 30 of the present disclosure is applied. FIG. 2 is a perspective view of the fuel injection pump 20 and the control device 30 extracted and viewed from the back side (the surface facing the engine body) of the fuel injection pump 20. For convenience of explanation, here, the side on which the fuel injection pump 20 is arranged with respect to the engine body is taken as the front.

[0017] As shown in Figure 1, the engine 10 has a fuel injection pump 20, and a control device 30 is connected to the fuel injection pump 20. Specifically, as shown in Figure 2, the fuel injection pump 20 is provided with a stop lever (fuel injection control lever) 21, and the control device 30 is connected to the stop lever 21 so that it can control the movement of the stop lever 21. The stop lever 21 switches between executing and stopping fuel injection by the fuel injection pump 20 by rotating it. Here, rotation means rotational motion that is rotatable in both directions but has a limited angular range. When power is supplied, the control device 30 moves the stop lever 21 to the injection execution side to enable the engine 10 to be driven, and when power is not supplied, it moves the stop lever 21 to the injection stop side to stop the engine 10.

[0018] Next, the basic configuration and operation of the control device 30 will be explained. Figure 3 is a perspective view showing only the control device 30. As shown in Figure 3, the control device 30 has a solenoid 31, a link mechanism 32, and a holding member 33. The solenoid 31 is the drive source of the control device 30, and a pull-type solenoid (which pulls the movable shaft 311 towards the sleeve 312 when energized) is used here. The link mechanism 32 connects the solenoid 31 and the stop lever 21, and switches the position of the stop lever 21 by driving the solenoid 31. Specifically, the link mechanism 32 converts the linear displacement of the movable shaft 311 in the solenoid 31 into the rotational displacement of the stop lever 21. The holding member 33 is a member that holds the solenoid 31 and the link mechanism 32 in a predetermined positional relationship.

[0019] The solenoid 31 has a movable shaft 311 and a sleeve 312, and is an actuator that slides the movable shaft 311 relative to the sleeve 312. The sleeve 312 of the solenoid 31 is fixed to the holding member 33.

[0020] The link mechanism 32 includes a slide pin (slide member) 321, a first link plate (rotating member) 322, a second link plate (rotating member) 323, a rotating shaft 324, a connecting shaft (connecting member) 325, and a transmission rod 326.

[0021] The slide pin 321 is connected to the movable shaft 311 of the solenoid 31 and is a component that slides integrally with the movable shaft 311. More specifically, the slide pin 321 and the movable shaft 311 are connected such that the longitudinal axis of the slide pin 321 and the longitudinal axis of the movable shaft 311 are parallel, and the slide pin 321 is slidable along its longitudinal axis.

[0022] The first link plate 322 and the second link plate 323 are members that rotate in conjunction with the sliding movement of the slide pin 321. The first link plate 322 and the second link plate 323 are pivotally supported on the rotation axis 324 so as to be rotatable, with the main surfaces of both link plates parallel to each other and the slide pin 321 sandwiched between the two link plates. The rotation axis 324 is fixed by the holding member 33.

[0023] The connecting shaft 325 is a component that connects the slide pin 321 to the first link plate 322 and the second link plate 323. Figure 4 is a plan view showing the connection mechanism between the slide pin 321 and the first link plate 322 and the second link plate 323 by the connecting shaft 325.

[0024] As shown in Figure 4, a small-diameter portion 321a is provided at the tip end of the slide pin 321 (opposite the solenoid 31), and this small-diameter portion 321a is inserted through a through hole 325a provided in the connecting shaft 325. Furthermore, a compression spring S, a washer W, and a retaining ring R are arranged on the tip end of the small-diameter portion 321a relative to the connecting shaft 325. Specifically, the compression spring S is placed between the connecting shaft 325 and the washer W, and the retaining ring R is placed on the outside (tip end) of the washer W to prevent the washer W and compression spring S from falling out of the small-diameter portion 321a.

[0025] In this case, the connecting shaft 325 receives a biasing force from the compression spring S and is pressed against the step at the base of the small-diameter portion 321a, maintaining the relative positional relationship between the slide pin 321 and the connecting shaft 325 for most of the range of movement of the slide pin 321. Furthermore, as shown in Figure 5, when the solenoid 31 is energized and the slide pin 321 is pulled towards the sleeve 312, the connecting shaft 325 can move slightly toward the tip against the biasing force of the compression spring S. This allows for some play between the slide pin 321 and the connecting shaft 325 when the solenoid 31 is energized. In other words, even after the stop lever 21 reaches the injection execution position and stops moving, the slide pin 321 can move slightly due to the aforementioned play, making it easier to reliably move the stop lever 21 to the injection execution position.

[0026] Furthermore, the connecting shaft 325 is positioned to pass through the elongated holes 322a and 323a (see Figures 6-9, etc.) provided in the first link plate 322 and the second link plate 323, respectively. This allows the connecting shaft 325 to transmit force to the first link plate 322 and the second link plate 323 via the elongated holes 322a and 323a, and the linear displacement of the connecting shaft 325 is converted into the rotational displacement of the first link plate 322 and the second link plate 323. Moreover, the rotation of the first link plate 322 and the second link plate 323 always occurs as a single unit, and the relative positions of the first link plate 322 and the second link plate 323 do not change due to the rotation.

[0027] One of the link plates, the first link plate 322 and the second link plate 323 (in this case, the first link plate 322), is longer than the other link plate (in this case, the second link plate 323). A connecting shaft 325 is connected to one end of the first link plate 322, with a rotating shaft 324 in between, and a transmission rod 326 is connected to the other end. One end of the transmission rod 326 is connected to the first link plate 322, and the other end is connected to the stop lever 21 of the fuel injection pump 20. As a result, when the first link plate 322 rotates, the movement is transmitted to the stop lever 21 via the transmission rod 326, making it possible to move the stop lever 21 between the injection execution position and the injection stop position. The transmission rod 326 is rotatably mounted to the first link plate 322 and the stop lever 21 within the rotational planes of the first link plate 322 and the stop lever 21.

[0028] One of the features of the control device 30 according to this embodiment 1 is that a support pin (support member) 331 is provided on the holding member 33 to suppress wear of parts due to repeated operation. In other words, if the control device 30 is not provided with a support pin 331, there is a problem with wear of parts. First, the problem of wear of parts when the support pin 331 is not provided will be explained with reference to Figures 6 and 7. Figures 6 and 7 are enlarged schematic diagrams of the area around the slide pin 321 to explain the problem of wear of parts in the control device 30, with Figure 6 showing the state of the solenoid 31 when it is not energized and Figure 7 showing the state of the solenoid 31 when it is energized. Note that the configuration shown in Figures 6 and 7 is the same as the control device 30 described above, except that it does not include a support pin 331, so the same parts will be used for the same parts as in the control device 30. Also, the solenoid 31 in Figures 6 and 7 is shown in cross-section.

[0029] As described above, the first link plate 322 and the second link plate 323 are each provided with elongated holes 322a and 323a, and the connecting shaft 325 is inserted through the elongated holes 322a and 323a. When the control device 30 is driven, the connecting shaft 325 is displaced within the elongated holes 322a and 323a, causing a change in its relative position to the first link plate 322 and the second link plate 323.

[0030] The solenoid 31 has a guide hole 312a inside the sleeve 312, and the movable shaft 311 slides along the guide hole 312a. In the solenoid 31, the inner diameter of the guide hole 312a is slightly larger than the outer diameter of the movable shaft 311 in order to ensure smooth sliding of the movable shaft 311. The solenoid 31 also has a spring inside the sleeve 312 to bias the movable shaft 311 and a coil to generate the driving force (electromagnetic force) of the movable shaft 311, but the spring and coil are not shown in Figures 6 and 7.

[0031] In the solenoid 31, in order to ensure smooth sliding movement of the movable shaft 311, it is preferable that the longitudinal axis of the guide hole 312a and the longitudinal axis of the movable shaft 311 are parallel to each other. When the solenoid 31 is not energized, that is, when the movable shaft 311 is pushed out from the sleeve 312, as shown in Figure 6, the connecting shaft 325 is located at the bottom of the elongated holes 322a and 323a, and the connecting shaft 325 is supported by the elongated holes 322a and 323a. At this time, the movable shaft 311 is supported by the elongated holes 322a and 323a via the connecting shaft 325 and the slide pin 321, and the state in which the longitudinal axes are parallel to each other with respect to the guide hole 312a is maintained.

[0032] On the other hand, when the solenoid 31 is energized, that is, when the movable shaft 311 is retracted into the sleeve 312, as shown in Figure 7, the connecting shaft 325 is not located at the bottom of the elongated holes 322a and 323a, and the elongated holes 322a and 323a do not support the connecting shaft 325. As a result, the movable shaft 311 tilts downwards at its tip due to the weight of the slide pin 321 and the connecting shaft 325 connected to it, and the longitudinal axis of the guide hole 312a and the longitudinal axis of the movable shaft 311 are no longer parallel. Of course, the tilted state of the movable shaft 311 shown in Figure 7 does not only occur when the movable shaft 311 is completely retracted into the sleeve 312, but also when the movable shaft 311 is within its range of motion in that vicinity.

[0033] In this way, as the tip of the movable shaft 311 tilts downward, the base of the movable shaft 311 rises, and the rear end of the movable shaft 311 comes into contact with the inner wall of the guide hole 312a. If the movable shaft 311 is repeatedly slid while in this contact state, wear of the parts at the contact point will be accelerated, which may lead to malfunction of the solenoid 31 and, consequently, malfunction of the fuel injection pump 20 by the control device 30.

[0034] Next, the operation when the support pin 331 is provided will be explained with reference to Figures 8 and 9. Figures 8 and 9 are enlarged schematic diagrams of the area around the slide pin 321 in the control device 30 of this embodiment 1, with Figure 8 showing the state of the solenoid 31 when it is not energized and Figure 9 showing the state of the solenoid 31 when it is energized.

[0035] As shown in Figures 8 and 9, the support pin 331 is positioned to contact the slide pin 321, more specifically the smaller diameter portion 321a, from below, both when the solenoid 31 is de-energized and when it is energized. This allows the support pin 331 to always support the sliding movement of the slide pin 321 from below. As a result, the movable shaft 311 is prevented from tilting due to the weight of the slide pin 321 and the connecting shaft 325, the longitudinal axis of the guide hole 312a and the longitudinal axis of the movable shaft 311 are kept parallel to each other, and wear of the solenoid 31 components is suppressed.

[0036] Furthermore, in order to suppress wear caused by contact with the slide pin 321, the support pin 331 may be provided with a roller 331a (see Figure 3) at the contact point with the slide pin 321, which is capable of rotating in accordance with the sliding movement of the slide pin 321.

[0037] [Embodiment 2] Another feature of the control device 30 according to this second embodiment is that the shape of the elongated holes 322a and 323a provided in the first link plate 322 and the second link plate 323 has been devised to suppress component wear due to repeated operation. In other words, depending on the shape of the elongated holes 322a and 323a, there is a problem of component wear. First, the shape of the elongated holes 322a and 323a that causes the problem of component wear will be explained with reference to Figure 10. Figure 10 is an enlarged schematic diagram of the area around the slide pin 321 to explain the problem of component wear, and shows the state when the solenoid 31 is energized.

[0038] In the state shown in Figure 10, the solenoid 31 is energized, causing the slide pin 321 to be pulled towards the sleeve 312. At this time, the connecting shaft 325 is pressed against the inner walls of the elongated holes 322a and 323a, specifically the inner wall on the pull-in side of the slide pin 321, by the biasing force F1 of the compression spring S. The biasing force F1 of the compression spring S acts in a direction parallel to the longitudinal axis of the slide pin 321.

[0039] When the solenoid 31 is not energized, the longitudinal axis of the slide pin 321 and the inner walls of the elongated holes 322a and 323a (specifically, the tangent at the point of contact with the connecting shaft 325) are perpendicular to each other (see Figures 6 and 8). On the other hand, when the solenoid 31 is energized, as shown in Figure 10, the inner walls of the elongated holes 322a and 323a are not perpendicular to the longitudinal axis of the slide pin 321, but are somewhat inclined. Therefore, the biasing force F1 of the compression spring S can be divided into a component force F2 perpendicular to the inner walls of the elongated holes 322a and 323a, and a component force F3 parallel to the inner walls of the elongated holes 322a and 323a.

[0040] Therefore, when the solenoid 31 is energized, the connecting shaft 325, which receives the biasing force F1, is displaced within the elongated holes 322a and 323a by the component force F3. In the example shown in Figure 10, the connecting shaft 325 is displaced upward along the elongated holes 322a and 323a. As a result of this displacement of the connecting shaft 325 within the elongated holes 322a and 323a, the slide pin 321 and the movable shaft 311 tilt so that their tips are raised, and the longitudinal axis of the guide hole 312a and the longitudinal axis of the movable shaft 311 are no longer parallel.

[0041] In this way, as the tip of the movable shaft 311 tilts upward, the base of the movable shaft 311 lowers, and the rear end of the movable shaft 311 comes into contact with the inner wall of the guide hole 312a. If the movable shaft 311 is repeatedly slid while in this contact state, wear of the parts at the contact point will be accelerated, which may lead to malfunction of the solenoid 31 and, consequently, malfunction of the fuel injection pump 20 by the control device 30.

[0042] Next, the operation of solving the above problem by modifying the shape of the elongated holes 322a and 323a will be explained with reference to Figures 11 and 12. Figures 11 and 12 are enlarged schematic diagrams of the area around the slide pin 321 in the control device 30 of this second embodiment, with Figure 11 showing the state of the solenoid 31 when it is not energized and Figure 12 showing the state of the solenoid 31 when it is energized.

[0043] In the configurations shown in Figures 11 and 12, the longitudinal axes of the elongated holes 322a and 323a are not straight lines but are bent midway. As a result, the elongated holes 322a and 323a are formed as bent elongated holes that are roughly in the shape of a "V". At both ends of the sliding range of the slide pin 321, the tangents at the point of contact between the inner walls of the elongated holes 322a and 323a and the connecting shaft 325 can be made perpendicular to the sliding direction of the slide pin 321.

[0044] As shown in Figure 11, when the solenoid 31 is not energized, the longitudinal axis of the slide pin 321 and the tangent L1 at the point of contact between the inner walls of the elongated holes 322a and 323a and the connecting shaft 325 are perpendicular. That is, the tangent L1 is perpendicular to the sliding direction of the slide pin 321. Furthermore, by making the elongated holes 322a and 323a bent elongated holes, even when the solenoid 31 is energized, as shown in Figure 12, the longitudinal axis of the slide pin 321 and the tangent L2 at the point of contact between the inner walls of the elongated holes 322a and 323a and the connecting shaft 325 can be made perpendicular (i.e., the tangent L2 is perpendicular to the sliding direction of the slide pin 321). This prevents the biasing force F1 of the compression spring S from generating a component force F3 in a direction parallel to the inner walls of the elongated holes 322a and 323a, thereby preventing the tip of the movable shaft 311 from tilting upward and suppressing wear of the solenoid 31 components.

[0045] Furthermore, it is preferable that the connecting shaft 325 is subjected to wear suppression measures, such as hard chrome plating, to suppress wear caused by contact with the elongated holes 322a and 323a. Alternatively, rollers that are driven to rotate in response to sliding movement within the elongated holes 322a and 323a may be provided at the contact points with the elongated holes 322a and 323a.

[0046] [Embodiment 3] In this third embodiment, we will describe another configuration that can prevent the tip end of the movable shaft 311 from lifting up, as described in the second embodiment above. Figures 13 and 14 are enlarged schematic diagrams of the area around the slide pin 321 in the control device 30 of this third embodiment, with Figure 13 showing the state of the solenoid 31 when it is not energized and Figure 12 showing the state of the solenoid 31 when it is energized.

[0047] In the configuration shown in Figures 13 and 14, a contact member 332 is provided that contacts the small-diameter portion 321a of the slide pin 321 from above throughout the entire sliding range of the slide pin 321, thereby restricting the lifting of the slide pin 321. The contact member 332 is preferably a leaf spring member that applies a spring force toward the slide pin 321 and is fixedly attached to the retaining member 33.

[0048] In the control device 30 according to this third embodiment, the small-diameter portion 321a of the slide pin 321 is always in contact with the contact member 332, thereby preventing the slide pin 321 from lifting up, and consequently preventing the movable shaft 311 connected to the slide pin 321 from lifting up. This makes it possible to suppress wear on the solenoid 31.

[0049] Furthermore, by making the contact member 332 a leaf spring member, it is possible to suppress the excessive clamping force on the small diameter portion 321a of the slide pin 321 between the support pin 331 and the contact member 332, thereby preventing the sliding movement of the slide pin 321 from being hindered.

[0050] In the embodiments 1 to 3 described above, the control device 30 is preferably directly attached to the engine 10 from the viewpoint of reducing the number of parts and improving positional accuracy relative to the fuel injection pump 20. In this case, a specific example is to use the bracket of the engine 10 as a retaining member 33 for the control device 30 (see Figure 1). When the control device 30 is directly attached to the engine 10 in this way, the control device 30 can be considered as a component included in the engine 10.

[0051] The embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. Therefore, the technical scope of this disclosure is not to be interpreted solely by the embodiments described above, but rather by the claims. [Explanation of symbols]

[0052] 10 Engines 20 Fuel injection pump 21. Stop lever (fuel injection control lever) 30 Control device 31 Solenoid 311 Movable axis 312 Sleeves 312a Guide hole 32 Link mechanism 321 Slide pin (sliding component) 321a Small diameter section 322 First link plate (rotating member) 323 Second link plate (rotating member) 322a,323a long hole 324 Rotation axis 325 Connecting shaft (connecting member) 325a through hole 326 Transmission Rod 33 Retaining member 331 Support pin (support member) 332 Contact Member

Claims

1. A control device that controls the fuel injection pump provided in the engine, Solenoid and, The system includes a link mechanism that connects the solenoid and the fuel injection control lever of the fuel injection pump, The link mechanism includes a sliding member connected to the solenoid and a rotating member that rotates in conjunction with the sliding movement of the sliding member. Furthermore, it is equipped with a support member that supports the slide member from below, The control device is characterized in that the rotating member has an elongated hole.

2. A control device according to claim 1, The control device is characterized in that the link mechanism slides integrally with the slide member and has a connecting member that is inserted into the elongated hole of the rotating member, thereby converting the sliding displacement of the slide member into the rotational displacement of the rotating member.

3. A control device according to claim 2, The control device is characterized in that the elongated hole is formed as a bent elongated hole in which the longitudinal axis is bent midway.

4. A control device according to claim 1, Furthermore, the control device is characterized by comprising a contact member that contacts the slide member from above.

5. An engine comprising a fuel injection pump and a control device that controls the fuel injection pump, The control device is the control device according to any one of claims 1 to 4, and is characterized in that it is attached to the engine via a bracket of the engine.

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