JP6685176B2 - Fuel supply pump - Google Patents

Description

  The present invention relates to a fuel supply pump having an intake valve.

  Heretofore, various proposals have been made regarding a flow path structure connecting an intake valve and a pressurizing chamber. Among them, for example, Japanese Patent Laid-Open No. 2010-169080 discloses a structure in which a plurality of through holes are provided in the circumferential direction of a stopper member of an intake valve to form a flow path to a pressurizing chamber. In addition, Japanese Patent Publication No. 2013-512399 discloses a structure in which an annular gap is provided on the outer circumference of the intake valve stopper to form a flow path to the pressurizing chamber.

JP, 2010-169080, A Japanese Patent Publication No. 2013-512399

  Recently, high output, low fuel consumption, and low cost of internal combustion engines have been energetically pursued. In response to this, fuel supply pumps are strongly required to have a large flow rate and high pressure of discharged fuel for high output and low fuel consumption, improvement of control accuracy, and reduction of processing man-hours for cost reduction. There is. Among them, the intake valve is one of the most important parts for satisfying these required performances, and improving its performance is an important issue. Therefore, as an example of dealing with an increase in the flow rate of discharged fuel and improving the control accuracy of the flow rate, there is a flow channel structure as shown in Patent Document 1. In this structure, a sufficient flow passage cross-sectional area is secured by providing a plurality of through holes so that pressure loss does not increase before and after the flow passage even when the flow rate of discharged fuel is increased.

  However, in this case, the number of processing man-hours increases with the number of through holes, and the cost may increase. Further, as an example of ensuring the flow passage cross-sectional area with a simpler structure, there is a flow passage structure as shown in Patent Document 2. In this structure, a sufficient flow passage cross-sectional area is secured by making the outer circumference of the intake valve stopper into an annular passage. On the other hand, since the suction valve stopper needs to have a function of restricting the displacement of the valve body, it needs to be fixed to the pump body or the like. However, the method is not disclosed in this structure, and there is a possibility that the function as the intake valve stopper cannot be sufficiently fulfilled.

  Therefore, an object of the present invention is to provide an intake valve that can secure a sufficient flow passage cross-sectional area with a simple structure that requires a small number of processing steps, and a low-cost fuel supply pump to which the intake valve is applied.

In order to solve the above-mentioned problems, the present invention comprises, as described in claim 1, a pump body 1 in which a pressurizing chamber 11 is formed, and a suction valve 30 arranged on the suction side of the pressurizing chamber 11. In the fuel supply pump, an overlapping portion 32d that is disposed between the pressurizing chamber 11 and the intake valve 30 and that overlaps the intake valve 30 in the intake valve axial direction, and an outer peripheral side of the outer peripheral side surface of the overlapping portion. And a plurality of fixing portions 32c that are integrally formed with the overlapping portion and fix the overlapping portion 32d, and are arranged on the outer peripheral side of the outer peripheral side surface of the overlapping portion 32d and the outer peripheral side surface of the overlapping portion 32d. A first flow path 32e is formed between the housing portion 31c and the first flow path 32e. The first flow path 32e is connected to the second flow path 32f on the pressurizing chamber side with respect to the pressurizing chamber side surface of the overlapping portion 32d, and at the same time, 1 channel 32 And the second flow path 32f is formed so as to be connected in succession by the housing part 31c, the first passage is formed annularly on the outer peripheral side of the overlapped portion, the fixing said second flow path adjacent Formed between the portion and the housing portion .

  According to the present invention, it is possible to provide an intake valve capable of ensuring a sufficient flow passage cross-sectional area with a simple structure having a small number of processing steps, and a low-cost fuel supply pump to which the intake valve is applied. Other configurations, operations, and effects of the present invention will be described in detail in the following embodiments.

3 is a cross-sectional view of a fuel supply pump that implements Embodiments 1 and 2. FIG. 1 is an overall configuration of a system that implements Examples 1 and 2. It is sectional drawing at the time of the fuel supply pump attachment which implements Example 1 and 2. It is sectional drawing in the suction | inhalation process of the solenoid valve which implements Example 1 and 2. FIG. FIG. 5 is a cross-sectional view of the discharge process of the solenoid valve for carrying out the first and second embodiments, and during energization. FIG. 4 is a cross-sectional view of a discharge process of a solenoid valve for carrying out Embodiments 1 and 2 when the power is not supplied. 3 is a perspective view of an intake valve stopper that implements Embodiment 1. FIG. 3A and 3B are a vertical cross-sectional view and a 45-degree cross-sectional view of a flow passage around a suction valve that implements the first embodiment. 7 is a perspective view of an intake valve stopper that implements Embodiment 2. FIG. FIG. 8 is a vertical cross-sectional view and a 45-degree cross-sectional view of a suction valve peripheral flow path for carrying out the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing an example of the overall configuration of a fuel supply system including a fuel supply pump to which the present invention is applicable. First, the configuration and operation of the entire system will be described with reference to this figure.
In FIG. 2, a portion 1 surrounded by a broken line indicates the fuel supply pump main body, and the mechanism and parts shown in the broken line indicate that the fuel supply pump main body 1 is integrally incorporated. Fuel is sent from the fuel tank 20 to the fuel supply pump main body 1 via the feed pump 21, and the pressurized fuel is sent from the fuel supply pump main body 1 to the injector 24 side. The engine control unit (control unit) 27 takes in the fuel pressure from the pressure sensor 26 and controls the feed pump 21, the electromagnetic coil 43 in the fuel supply pump main body 1 and the injector 24 to optimize this.

  In FIG. 2, the fuel in the fuel tank 20 is first pumped up by the feed pump 21 based on the control signal S1 from the engine control unit (control unit) 27, pressurized to an appropriate feed pressure, and pumped through the suction pipe 28. 1 is sent to the low pressure fuel suction port (suction joint) 10a. The fuel that has passed through the low-pressure fuel suction port 10a reaches the suction port 31b of the electromagnetic suction valve 300 that constitutes the variable capacity mechanism via the pressure pulsation reducing mechanism 9 and the suction passage 10d. The pressure pulsation reducing mechanism 9 communicates with the annular low-pressure fuel chamber 7a that makes the pressure variable by interlocking with the plunger 2 that reciprocates by a cam mechanism (not shown) of the engine, so that the electromagnetic suction valve 300 has The pulsation of the fuel pressure sucked into the suction port 31b is reduced.

  The fuel flowing into the suction port 31b of the electromagnetic suction valve 300 passes through the suction valve 30 and flows into the pressurizing chamber 11. The valve position of the intake valve 30 is determined by controlling the electromagnetic coil 43 in the fuel supply pump body 1 based on the control signal S2 from the engine control unit (control section) 27. In the pressurizing chamber 11, the cam mechanism (not shown) of the engine gives reciprocating power to the plunger 2. Due to the reciprocating motion of the plunger 2, fuel is sucked from the suction valve 30 in the descending process of the plunger 2, and the sucked fuel is pressurized in the ascending process of the plunger 2, and the pressure sensor 26 is attached via the discharge valve mechanism 8. Fuel is pressure-fed to the common rail 23 in which it is present. Thereafter, the injector 24 injects fuel into the engine based on the control signal S3 from the engine control unit (control unit) 27.

  The discharge valve mechanism 8 provided at the outlet of the pressurizing chamber 11 includes a discharge valve seat 8a, a discharge valve 8b that contacts and separates from the discharge valve seat 8a, and a discharge valve 8b that urges the discharge valve 8b toward the discharge valve seat 8a. It is composed of a valve spring 8c and the like. According to the discharge valve mechanism 8, the discharge valve 8b is opened when the internal pressure of the pressurizing chamber 11 is higher than the pressure on the discharge passage 12 side on the downstream side of the discharge valve 8b and the reaction force defined by the discharge valve spring 8c is overcome. The pressurized fuel is pressure-fed and supplied from the pressurizing chamber 11 to the discharge passage 12 side.

  Further, regarding each component constituting the electromagnetic intake valve 300 of FIG. 2, 30 is an intake valve, 35 is a rod for controlling the position of the intake valve 30, 36 is an anchor portion, 33 is an intake valve spring, 40 is a rod biasing spring, Reference numeral 41 is an anchor portion urging spring. According to this mechanism, the suction valve 30 is biased in the valve closing direction by the suction valve spring 33, and is biased in the valve opening direction by the rod biasing spring 40 via the rod 35. Further, the anchor portion 36 is biased in the valve closing direction by the anchor portion biasing spring. The valve position of the intake valve 30 is controlled by driving the rod 35 with the electromagnetic coil 43.

  As described above, in the fuel supply pump 1, the electromagnetic coil 43 in the fuel supply pump main body 1 is controlled by the control signal S2 given to the electromagnetic suction valve 300 by the engine control unit (control unit) 27, and the common rail is provided via the discharge valve mechanism 8. The fuel flow rate is discharged so that the fuel pressure-fed to 23 becomes a desired supply fuel.

  Further, in the fuel supply pump 1, the pressurizing chamber 11 and the common rail 23 are connected by the relief valve 100. The relief valve 100 is a valve mechanism arranged in parallel with the discharge valve mechanism 8. In the relief valve 100, when the pressure on the common rail 23 side rises above the set pressure of the relief valve 100, the relief valve 100 opens and the fuel is returned to the pressurizing chamber 11 of the fuel supply pump 1. Prevents abnormal high pressure conditions.

  The relief valve 100 forms a high-pressure passage 110 that connects the discharge passage 12 on the downstream side of the discharge valve 8b in the fuel supply pump body 1 and the pressurizing chamber 11, and is provided so as to bypass the discharge valve 8b. It has been done. The high-pressure flow passage 110 is provided with a relief valve 102 that restricts the flow of fuel from the discharge flow passage to the pressurizing chamber 11 only in one direction. The relief valve 102 is pressed against the relief valve seat 101 by a relief spring 105 that generates a pressing force, and the pressure difference between the pressurizing chamber 11 and the high-pressure flow passage 110 is a specified pressure determined by the relief spring 105. When the above is completed, the relief valve 102 is set to separate from the relief valve seat 101 and open.

  As a result, when the common rail 23 has an abnormally high pressure due to a failure of the electromagnetic suction valve 300 of the fuel supply pump 1, when the differential pressure between the discharge passage 110 and the pressurizing chamber 11 becomes equal to or higher than the opening pressure of the relief valve 102. The relief valve 102 is opened, and the fuel having an abnormally high pressure is returned from the discharge flow passage 110 to the pressurizing chamber 11 to protect the high pressure pipes such as the common rail 23.

  FIG. 1 is a diagram showing a specific example of a fuel supply pump main body 1 that is mechanically integrated. According to this figure, the plunger 2 that reciprocates (up and down in this case) by the cam mechanism (not shown) of the engine in the central height direction in the figure is arranged in the cylinder 6, and the inside of the cylinder 6 above the plunger is arranged. A pressurizing chamber 11 is formed in the.

  Further, according to this figure, the mechanism on the electromagnetic suction valve 300 side is arranged on the left side in the center of the drawing, and the discharge valve mechanism 8 is arranged on the right side of the center in the drawing. Further, a low-pressure fuel suction port 10a, a pressure pulsation reducing mechanism 9, a suction passage 10d, etc. are arranged on the upper portion of the drawing as a mechanism on the fuel suction side. Further, the plunger internal combustion engine side mechanism 150 is described in the lower center of FIG. Since the plunger internal combustion engine side mechanism 150 is a portion that is embedded and fixed in the internal combustion engine body as shown in FIG. 3, it will be referred to as an attachment root portion here. The relief valve 100 mechanism is not shown in the display cross section of FIG. Although the relief valve 100 mechanism can be displayed within the display cross section at another angle, its description and display are omitted because it is not directly related to the present invention.

  The detailed description of each part in FIG. 2 will be described later. First, the mounting of the mounting root will be described with reference to FIG. FIG. 3 shows a state in which the mounting root portion (plunger internal combustion engine side mechanism) 150 is embedded and fixed in the internal combustion engine body. However, in FIG. 3, since the description is centered on the attachment root 150, the description of other parts is omitted. In FIG. 3, 90 indicates a thick portion of the cylinder head of the internal combustion engine. In the cylinder head 90 of the internal combustion engine, a mounting root mounting hole 95 is formed in advance. The mounting root portion mounting hole 95 has a two-step diameter corresponding to the shape of the mounting root portion 150, and the mounting root portion 150 is fitted and disposed in the root mounting hole 95.

  Then, the mounting root 150 is airtightly fixed to the cylinder head 90 of the internal combustion engine. In the airtight fixed arrangement example of FIG. 3, the fuel supply pump is in close contact with the flat surface of the cylinder head 90 of the internal combustion engine using the flange 1e provided on the pump body 1, and is fixed by the plurality of bolts 91. In addition, the mounting flange 1e is welded to the pump body 1 at the welded portion 1f along the entire circumference to form an annular fixed portion. In this embodiment, laser welding is used to weld the welded portion 1f. Further, the O-ring 61 is fitted into the pump body 1 for the purpose of sealing between the cylinder head 90 and the pump body 1 to prevent the engine oil from leaking to the outside.

  The plunger root 150 thus airtightly fixed is provided with the tappet 92 which converts the rotational movement of the cam 93 attached to the camshaft of the internal combustion engine into vertical movement at the lower end 2b of the plunger 2 and transmits the vertical movement to the plunger 2. Has been. The plunger 2 is pressed against the tappet 92 by the spring 4 via the retainer 15. This causes the plunger 2 to reciprocate up and down in accordance with the rotational movement of the cam 93.

  Further, the plunger seal 13 held at the lower end of the inner circumference of the seal holder 7 is installed in a slidable contact with the outer circumference of the plunger 2 in the lower part of the cylinder 6 in the drawing, and the plunger low pressure chamber 7a of the annular low-pressure fuel chamber 7a. Even if the plunger 2 slides, the fuel can be sealed to prevent the fuel from leaking to the outside. At the same time, the lubricating oil (including the engine oil) that lubricates the sliding parts in the internal combustion engine is prevented from flowing into the pump body 1.

  As shown in FIG. 3, the plunger root 150 arranged in an airtight manner reciprocates in the cylinder 6 as the plunger 2 inside the plunger root 150 rotates with the internal combustion engine. The function of each part associated with this reciprocating motion will be described by returning to FIG. In FIG. 1, the fuel supply pump main body 1 is a cylinder whose end portion (upper side in FIG. 1) is formed in a bottomed cylindrical shape so as to guide the reciprocating movement of the plunger 2 and to form a pressurizing chamber 11 therein. 6 is attached. Further, the pressurizing chamber 11 has an annular groove 6a on the outer peripheral side so as to communicate with the electromagnetic suction valve 300 for supplying fuel and the discharge valve mechanism 8 for discharging fuel from the pressurizing chamber 11 to the discharge passage. A plurality of communication holes 6b for communicating the groove 6a with the pressure chamber are provided.

  The outer diameter of the cylinder 6 is press-fitted and fixed to the fuel supply pump main body 1, and the cylinder 6 is sealed with a press-fitting cylindrical surface so that fuel pressurized from the gap between the cylinder 6 and the fuel supply pump main body 1 does not leak to the low pressure side. Further, a small diameter portion 6c is provided on the outer diameter of the cylinder 6 on the pressure chamber side. When the fuel in the pressurizing chamber 11 is pressurized, the cylinder 6 exerts a force on the low-pressure fuel chamber 10c side. However, by providing the pump body 1 with the small diameter portion 1a, the cylinder 6 escapes to the low-pressure fuel chamber 10c side. To prevent that. By bringing their surfaces into contact with each other in a plane in the axial direction, in addition to the sealing of the contact cylindrical surfaces of the fuel supply pump main body 1 and the cylinder 6, a double sealing function is achieved.

  A damper cover 14 is fixed to the head of the fuel supply pump body 1. The damper cover 14 is provided with an intake joint 51 and forms a low-pressure fuel intake port 10a. The fuel that has passed through the low-pressure fuel suction port 10a passes through the filter 52 fixed inside the suction joint 51, and reaches the suction port 31b of the electromagnetic suction valve 300 through the pressure pulsation reduction mechanism 9 and the low-pressure fuel flow path 10d. .

  The suction filter 52 in the suction joint 51 has a function of preventing foreign matter existing between the fuel tank 20 and the low-pressure fuel suction port 10a from being absorbed into the fuel supply pump by the flow of fuel.

  Since the plunger 2 has the large diameter portion 2a and the small diameter portion 2b, the volume of the annular low pressure fuel chamber 7a is increased or decreased by the reciprocating motion of the plunger. Since the increase / decrease in volume is communicated with the low pressure fuel chamber 10 through the fuel passage 1d (FIG. 3), the annular low pressure fuel chamber 7a moves to the low pressure fuel chamber 10 when the plunger 2 descends, and the low pressure fuel increases when the plunger 2 rises. A fuel flow is generated from the fuel chamber 10 to the annular low pressure fuel chamber 7a. As a result, it is possible to reduce the flow rate of fuel into and out of the pump in the suction process or the returning process of the pump, and it has a function of reducing pulsation.

  The low pressure fuel chamber 10 is provided with a pressure pulsation reducing mechanism 9 that reduces the pressure pulsation generated in the fuel supply pump from spreading to the fuel pipe 28 (FIG. 2). When the fuel once flowing into the pressurizing chamber 11 is returned to the suction passage 10d (suction port 31b) through the suction valve body 30 in the valve open state for capacity control, it is returned to the suction passage 10d (suction port 31b). The generated fuel causes a pressure pulsation in the low pressure fuel chamber 10. However, the pressure pulsation reducing mechanism 9 provided in the low-pressure fuel chamber 10 is formed by a metal damper in which two corrugated disc-shaped metal plates are bonded together at their outer circumferences and an inert gas such as argon is injected into the inside. However, the pressure pulsation is absorbed and reduced as the metal damper expands and contracts. Reference numeral 9b is a mounting member for fixing the metal damper to the inner peripheral portion of the fuel supply pump main body 1. Since it is installed on the fuel passage, a plurality of holes are provided to allow fluid to freely flow between the front and back of the mounting member 9b. I am able to do it.

  The discharge valve mechanism 8 provided at the outlet of the pressurizing chamber 11 includes a discharge valve seat 8a, a discharge valve 8b that contacts and separates from the discharge valve seat 8a, and a discharge valve spring that biases the discharge valve 8b toward the discharge valve seat 8a. 8c, a discharge valve holder 8d for accommodating the discharge valve 8b and the discharge valve seat 8a, and the discharge valve seat 8a and the discharge valve holder 8d are welded to each other at the contact portion 8e to form an integrated discharge valve mechanism 8. Is forming. A stepped portion 8f that forms a stopper that restricts the stroke of the discharge valve 8b is provided inside the discharge valve holder 8d.

  In FIG. 1, when there is no fuel pressure difference between the pressurizing chamber 11 and the fuel discharge port 12, the discharge valve 8b is pressed against the discharge valve seat 8a by the urging force of the discharge valve spring 8c and is in the closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the fuel outlet 12, the discharge valve 8b opens against the discharge valve spring 8c, and the fuel in the pressurizing chamber 11 releases the fuel. High-pressure discharge is carried out to the common rail 23 via 12. When the discharge valve 8b opens, it contacts the discharge valve stopper 8f, and the stroke is limited. Therefore, the stroke of the discharge valve 8b is appropriately determined by the discharge valve stopper 8d. As a result, it is possible to prevent the fuel discharged at high pressure to the fuel discharge port 12 from flowing back into the pressurizing chamber 11 again due to the stroke being too large and the closing of the discharge valve 8b being delayed, thereby reducing the efficiency of the fuel supply pump. Can be suppressed. Further, when the discharge valve 8b repeats the opening and closing movements, the discharge valve 8b is guided by the inner peripheral surface of the discharge valve holder 8d so as to move only in the stroke direction. By doing so, the discharge valve mechanism 8 serves as a check valve that limits the flow direction of fuel.

Next, the structure on the electromagnetic intake valve 300 side, which is the main part of the present invention, will be described with reference to FIGS. 4, 5, and 6. It should be noted that FIG. 4 shows a state in the suction process among the suction, return, and discharge processes in pump operation, and FIGS. 5 and 6 show a state in the discharge process. First, the structure on the electromagnetic suction valve 300 side will be described with reference to FIG. The structure on the electromagnetic intake valve 300 side is mainly composed of an intake valve portion A mainly composed of the intake valve 30, a solenoid mechanism portion B mainly composed of a rod 35 and an anchor portion 36, and an electromagnetic coil 43. The intake valve section A is composed of an intake valve 30, an intake valve seat 31, an intake valve stopper 32, an intake valve biasing spring 33, and an intake valve holder 34. Of these, the intake valve seat 31 is a cylindrical type, and has a seat portion 31a in the axial direction on the inner peripheral side and a plurality of intake passage portions 31b radially around the axis of the cylinder.

  The suction valve holder 34 has claws radially extending in two or more directions, and the claw outer peripheral side is coaxially fitted and held on the inner peripheral side of the suction valve seat 31. Further, a suction valve stopper 32, which is cylindrical and has a brim shape at one end, is fitted and held on the inner cylindrical surface of the suction valve holder 34.

  The suction valve biasing spring 33 is arranged on the inner peripheral side of the suction valve stopper 32 in a small diameter portion for partially stabilizing one end of the spring coaxially, and the suction valve 30 is connected to the suction valve seat portion 31a and the suction valve seat portion 31a. A suction valve biasing spring 33 is fitted in the valve guide portion 30b between the valve stoppers 32. The suction valve biasing spring 33 is a compression coil spring and is installed so that the biasing force acts in the direction in which the suction valve 30 is pressed against the suction valve seat portion 31a. Not limited to the compression coil spring, any form may be used as long as it can obtain the biasing force, and a leaf spring having a biasing force integrated with the suction valve may be used.

  By configuring the intake valve portion A in this manner, in the intake process of the pump, the fuel that has passed through the intake passage 31b and enters inside passes between the intake valve 30 and the seat portion 31a, and The fuel flows into the pressurizing chamber through the outer peripheral side and between the claws of the suction valve holder 34 and the passage of the fuel supply pump body 1 and the cylinder. In the discharge process of the pump, the intake valve 30 seals the intake valve seat portion 31a so as to function as a check valve for preventing backflow of fuel to the inlet side.

  In order to smooth the movement of the suction valve 30, a passage 32a is provided in order to release the hydraulic pressure on the inner peripheral side of the suction valve stopper according to the movement of the suction valve 30.

  The axial movement amount 30e of the suction valve 30 is limited by the suction valve stopper 32. This is because if the amount of movement is too large, the reverse flow rate increases due to the response delay when the intake valve 30 is closed, and the performance of the pump deteriorates. The regulation of the movement amount can be defined by the axial dimension and the fixed position of the suction valve seat 31a, the suction valve 30, and the suction valve stopper 32.

  The suction valve stopper 32 is provided with a protrusion 32b to reduce the contact area with the suction valve stopper 32 when the suction valve 32 is open. This is because the intake valve 32 is likely to be separated from the intake valve stopper 32 when the valve open state is changed to the valve closed state, that is, the valve closing response is improved. When there is no annular protrusion, that is, when the contact area is large, a large squeeze force acts between the suction valve 30 and the suction valve stopper 32, and the suction valve 30 becomes difficult to separate from the suction valve 32.

  The intake valve 30, the intake valve seat 31a, and the intake valve stopper 32 are made of a heat-treated martensitic stainless steel, which has high strength, high hardness, and excellent corrosion resistance, because collisions occur repeatedly during operation. Austenitic stainless steel is used for the intake valve spring 33 and the intake valve holder 34 in consideration of corrosion resistance.

  Next, the solenoid mechanism section B will be described. The solenoid mechanism portion B includes a rod 35 that is a movable portion, an anchor portion 36, a rod guide 37 that is a fixed portion, an outer core 38, a fixed core 39, a rod urging spring 40, and an anchor portion urging spring 41.

  The rod 35, which is a movable portion, and the anchor portion 36 are configured as separate members. The rod 35 is slidably held in the axial direction on the inner peripheral side of the rod guide 37, and the inner peripheral side of the anchor portion 36 is slidably held on the outer peripheral side of the rod 35. That is, both the rod 35 and the anchor portion 36 are configured to be slidable in the axial direction within a geometrically restricted range.

  The anchor portion 36 has one or more through holes 36a penetrating in the axial direction of the component in order to move smoothly in the fuel in the axial direction, and the movement limitation due to the pressure difference before and after the anchor portion is eliminated as much as possible. .

  The rod guide 37 is radially inserted into an inner peripheral side of a hole into which the intake valve of the fuel supply pump main body 1 is inserted, and axially abutted against one end of the intake valve seat. It is arranged such that it is sandwiched between the outer core 38 welded and fixed to the main body 1 and the fuel supply pump main body 1. Like the anchor portion 36, the rod guide 37 is also provided with a through hole 37a penetrating in the axial direction, so that the pressure of the fuel chamber on the anchor portion side moves the anchor portion so that the anchor portion can move freely and smoothly. It is structured so as not to interfere.

  The outer core 38 has a thin-walled cylindrical shape on the side opposite to the portion to be welded to the fuel supply pump body, and is fixed by welding with the fixed core 39 inserted into the inner peripheral side thereof. A rod urging spring 40 is arranged on the inner peripheral side of the fixed core 39 with the small diameter portion as a guide, the rod 35 contacts the intake valve 30, and the intake valve is pulled away from the intake valve seat portion 31a, that is, the intake valve. A biasing force is applied in the valve opening direction.

  The anchor portion urging spring 41 is arranged to apply a urging force to the anchor portion 36 in the direction of the rod flange 35a while maintaining coaxiality by inserting the one end into a central bearing portion 37b having a cylindrical diameter provided on the center side of the rod guide 37. I am trying. The movement amount 36e of the anchor portion 36 is set to be larger than the movement amount 30e of the suction valve 30. This is because the suction valve 30 is surely closed.

  Since the rod 35 and the rod guide 37 slide against each other and the rod 35 repeatedly collides with the suction valve 30, martensitic stainless steel subjected to heat treatment is used in consideration of hardness and corrosion resistance. The anchor portion 36 and the fixed core 39 are made of magnetic stainless steel to form a magnetic circuit, and the rod urging spring 40 and the anchor portion urging spring 41 are made of austenitic stainless steel in consideration of corrosion resistance.

  According to the above configuration, the intake valve portion A and the solenoid mechanism portion B are configured by organically disposing three springs. The suction valve biasing spring 33 configured in the suction valve portion A, the rod biasing spring 40 configured in the solenoid mechanism portion B, and the anchor portion biasing spring 41 correspond to this. In this embodiment, any spring is a coil spring, but any spring can be used as long as it can obtain a biasing force.

The relationship between these three spring forces is configured by the following equation.
(Equation 1)
Rod urging spring 40 force> Anchor portion urging spring 41 force + suction valve urging spring 33 force + force to close intake valve by fluid (1)
According to the relationship of the equation (1), when the power is not applied, the springs cause the rod 35 to act as a force f1 in a direction of separating the intake valve 30 from the intake valve seat portion 31a, that is, in a direction of opening the valve. From the equation (1), the force f1 in the valve opening direction is expressed by the following equation (2).
(Equation 2)
f1 = rod urging spring force− (anchor portion urging spring force + suction valve urging spring force + force that fluid tries to close the suction valve) (2)

  Finally, the configuration of the coil portion C will be described. The coil portion C includes a first yoke 42, an electromagnetic coil 43, a second yoke 44, a bobbin 45, a terminal 46, and a connector 47. A coil 43 in which a copper wire is wound a plurality of times around the bobbin 45 is arranged so as to be surrounded by the first yoke 42 and the second yoke 44, and is molded and fixed integrally with the connector which is a resin member. One end of each of the two terminals 46 is electrically connected to each end of the copper wire of the coil. Similarly, the terminal 46 is also molded integrally with the connector so that the remaining end can be connected to the engine control unit side.

  The hole portion at the center of the first yoke 42 of the coil portion C is press-fitted and fixed to the outer core 38. At that time, the inner diameter side of the second yoke 44 is in contact with the fixed core 39 or in the vicinity of a slight clearance.

  Both the first yoke 42 and the second yoke 44 are made of a magnetic stainless material in order to form a magnetic circuit and in consideration of corrosion resistance, and the bobbin 45 and the connector 47 are made of high strength heat resistant resin in consideration of strength characteristics and heat resistance characteristics. . The coil 43 is copper, and the terminal 46 is brass plated with metal.

  By configuring the solenoid mechanism portion B and the coil portion C as described above, the outer core 38, the first yoke 42, the second yoke 44, the fixed core 39, and the anchor portion 36, as shown by the arrows in FIG. When a magnetic circuit is formed by applying a current to the coil, a magnetic attraction force is generated between the fixed core 39 and the anchor portion 36, and a force attracting each other is generated. In the outer core 38, since the fixed core 39 and the anchor portion 36 make the axial portions where the magnetic attraction force is generated to be as thin as possible, almost all of the magnetic flux passes between the fixed core 39 and the anchor portion 36. The magnetic attraction force can be efficiently obtained.

  When the magnetic attraction force exceeds the force f1 in the opening direction of the valve of the formula (2), the anchor part 36, which is a movable part, is moved toward the fixed core 39 together with the rod 35, and the core 39 and the anchor part. 36 makes contact and allows contact to continue.

  According to the above-described structure of the fuel supply pump of the present invention, the following operations are performed in each process of suction, return, and discharge in pump operation.

  First, the inhalation process will be described. In the suction process, the rotation of the cam 93 in FIG. 3 causes the plunger 2 to move in the direction of the cam 93 (the plunger 2 descends). That is, the position of the plunger 2 has moved from top dead center to bottom dead center. In the suction process state, for example, referring to FIG. 1, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases. In this step, when the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure in the suction passage 10d, the fuel passes through the suction valve 30 in the open state, the communication hole 1b provided in the fuel supply pump main body 1 and the cylinder. It passes through the outer peripheral passages 6 a and 6 b and flows into the pressurizing chamber 11.

  The positional relationship between the respective parts on the electromagnetic suction valve 300 side in the suction process is shown in FIG. 4, which will be described with reference to FIG. In this state, the electromagnetic coil 43 remains in the non-energized state and the magnetic biasing force is not acting. Therefore, the suction valve 30 is pressed by the rod 35 by the urging force of the rod urging spring 40, and remains open.

  Next, the returning step will be described. In the returning process, the plunger 2 moves in the upward direction by the rotation of the cam 93 in FIG. That is, the position of the plunger 2 has begun to move from the bottom dead center toward the top dead center. At this time, the volume of the pressurizing chamber 11 decreases with the compressive movement of the plunger 2 after the intake, but in this state, the fuel once sucked into the pressurizing chamber 11 is sucked again through the intake valve 30 in the open state. Since it is returned to the passage 10d, the pressure in the pressurizing chamber does not rise. This process is called a returning process.

  In this state, when a control signal from the engine control unit (control unit) 27 is applied to the electromagnetic suction valve 300, the returning process shifts to the discharging process. When the control signal is applied to the electromagnetic suction valve 300, a magnetic attraction force is generated in the coil part C, and this acts on each part. FIG. 5 shows the positional relationship between the respective parts on the side of the electromagnetic suction valve 300 when the magnetic attraction force is applied, which will be described with reference to FIG. In this state, a magnetic circuit is formed by the outer core 38, the first yoke 42, the second yoke 44, the fixed core 39, and the anchor portion 36, and when a current is applied to the coil, magnetic attraction is generated between the fixed core 39 and the anchor portion 36. A force is generated and a force is drawn toward each other. When the anchor portion 36 is sucked by the fixed core 39, which is the fixed portion, the rod 35 moves in a direction away from the suction valve 30 by the locking mechanism of the anchor portion 36 and the rod collar portion 35a. At this time, the suction valve 30 is closed by the urging force of the suction valve urging spring 33 and the fluid force of the fuel flowing into the suction passage 10d. After the valve is closed, the fuel pressure in the pressurizing chamber 11 rises with the upward movement of the plunger 2, and when the pressure becomes equal to or higher than the pressure of the fuel discharge port 12, high pressure fuel is discharged through the discharge valve mechanism 8 to the common rail 23. Supplied. This process is called a discharge process.

  That is, the compression process of the plunger 2 (the rising process from the lower start point to the upper start point) includes a returning process and a discharging process. Then, by controlling the timing of energizing the coil 43 of the electromagnetic suction valve 300, the amount of high-pressure fuel discharged can be controlled. If the timing of energizing the electromagnetic coil 43 is advanced, the ratio of the returning process and the ratio of the discharging process in the compression process are small. That is, less fuel is returned to the suction passage 10d, and more fuel is discharged under high pressure. On the other hand, if the timing of energization is delayed, the ratio of the returning process is large and the ratio of the discharging process is small during the compression process. That is, much fuel is returned to the suction passage 10d, and less fuel is discharged under high pressure. The timing of energizing the electromagnetic coil 43 is controlled by a command from the engine control unit (control unit) 27.

  With the above configuration, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the power supply timing to the electromagnetic coil 43.

  FIG. 6 shows the positional relationship of each part on the electromagnetic suction valve 300 side in the discharge process. Here, a diagram of a non-energized state in which the electromagnetic coil 43 is de-energized in a state where the suction valve is closed after the pressure in the pressurizing chamber is sufficiently increased is shown. In this state, in preparation for the process of the next cycle, a system is prepared to effectively perform the next generation and action of the magnetic attraction force. This structure is characterized by the establishment of this system.

  In the present embodiment, an example will be described in which the intake valve holder 34 is integrated with the intake valve stopper 32 and the flow path structure of the present invention is formed by the shape thereof. The shape of the intake valve stopper 32 in this embodiment is shown in FIG. Further, in the present embodiment, it is intended to secure a sufficient flow passage cross-sectional area with a simple structure having a small number of processing steps and to prevent an increase in pressure loss even when the discharge fuel has a large flow rate. The detailed structure for this will be described below. This makes it possible to provide an electromagnetic suction valve that realizes highly accurate flow rate control, and a low-cost fuel supply pump that uses the electromagnetic suction valve.

  The suction valve stopper 32 is provided with a fixing portion 32c on the outermost periphery thereof, and is fitted and held in the inner peripheral cylindrical surface of the housing portion 31c at this portion. Further, a disc-shaped overlapping portion 32d is provided near the central portion, and the suction valve 30 is arranged on this side surface.

  FIG. 8 shows a sectional view of the intake valve portion A when the intake valve stopper 32 shown in FIG. 7 is assembled. The vertical section is shown in the upper section and the 45-degree section is shown in the lower section. An overlapping portion 32d that is disposed between the pressurizing chamber 11 and the suction valve 30 and that overlaps with the suction valve 30 in the suction valve axial direction is formed integrally with the overlapping portion 32d on the outer peripheral side of the outer peripheral side surface of the overlapping portion 32d. , And a plurality of fixing portions 32c for fixing the overlapping portion 32d. And the 1st flow path 32e is formed between the outer peripheral side surface of the overlapping part 32d and the housing part 31c arrange | positioned further outer peripheral side than the outer peripheral side surface of the overlapping part 32d, and the 1st flow path 32e forms the overlapping part 32d. The first flow path 32e and the second flow path 32f are formed so as to be connected to the second flow path 32f on the pressurization chamber side with respect to the side surface of the pressurization chamber, and to be continuously connected to the housing portion 31c. Further, the plurality of fixing portions 32c are configured to be located on the pressurizing chamber side with respect to the suction valve side surface of the overlapping portion 32d, and the outer peripheral side surface of the overlapping portion 32d and the suction valve side of the plurality of fixing portions 32c are arranged. The surface forms a first flow path 32e, and a second flow path 32f that connects the first flow path 32e and the pressurizing chamber 11 is formed between the adjacent fixing portions 32d.

  By adopting this configuration, it is possible to form the flow path without performing the hole processing that requires a large number of processing steps and also to fix the intake valve stopper 32 to the housing portion 31c, which is advantageous from the viewpoint of cost reduction. is there.

  Further, the thickness of the plurality of fixing portions 32c in the intake valve axial direction is configured to be thinner than the thickness of the overlapping portion 32d in the suction valve axial direction, and the surface of the plurality of fixing portions 32c on the pressurizing chamber side is formed. You may comprise so that it may be located in a suction valve side rather than the surface of the overlapping part 32d by the side of a pressurization chamber.

  The flow passage cross-sectional area of the second flow passage 32f is smaller than that of the first flow passage 32e by the amount of the fixing portion 32c, and the contribution to the pressure loss is large. As described above, by reducing the thickness of the plurality of fixing portions 32c, it is possible to shorten the axial distance of the second flow passage 32f, which greatly contributes to the pressure loss, which is advantageous from the viewpoint of reducing the pressure loss. .

  Further, as assumed in the present embodiment, a part of the overlapping portion 32d comes into contact with the intake valve 30 to form the intake valve stopper 32 that restricts the movement in the valve opening direction, or the overlapping portion 32d. However, a spring holding portion 32h that holds the suction valve spring 33 that biases the suction valve 30 in the valve closing direction may be formed. Further, regarding the method of fixing the suction valve stopper 32, the plurality of fixing portions 32d are configured such that the press-fitting portion 32i press-fitted to the inner peripheral surface of the hole portion 1c formed in the pump body 1 or the inner peripheral surface of the housing portion 31c. To prepare for. The overlapping portion 32d and the plurality of fixing portions 32c are preferably formed by pressing parts or forging parts.

  As a result, the structure of the intake valve portion A can be simplified by integrating the plurality of functions in the intake valve stopper 32 and effectively utilizing the space. In addition, by forming the suction valve stopper 32 by a press manufacturing method or a forging manufacturing method, which requires less processing than hole processing, the number of processing steps can be reduced, which is advantageous from the viewpoint of cost reduction.

  Regarding the arrangement of the fixing portion 32c, the plurality of fixing portions 32c are arranged at a predetermined interval in the circumferential direction on the outer peripheral side of the outer peripheral side surface of the overlapping portion 32d so as to overlap the second flow passage 32f. It is formed on the outer peripheral side of the outermost peripheral end of the outer peripheral side surface of the portion 32d. Further, the outermost peripheral end of the outer peripheral side surface of the overlapping portion 32c is configured to be located on the outer peripheral side of the outermost peripheral end of the outer peripheral surface of the intake valve 30.

  By doing so, it is possible to prevent the fuel flow from the pressurizing chamber 11 from directly hitting the intake valve 30 and increasing the fluid force in the valve closing direction to cause erroneous valve closing. As a result, improvement in flow rate control accuracy can be achieved.

  In general, if the configuration of this embodiment is used, a sufficient flow passage cross-sectional area can be secured with a simple structure with a small number of processing steps, and an increase in pressure loss can be prevented even when the flow rate of the discharged fuel is increased, resulting in high accuracy. It is possible to provide an intake valve that realizes various flow rate control and a low-cost fuel supply pump to which the intake valve is applied.

In this embodiment, a modification of the first embodiment will be described. FIG. 9 shows the shape of the intake valve stopper 32 according to this embodiment. The feature of the present embodiment is that the portion (illustrated by the dotted line) between a plurality of adjacent fixing portions 32c is excluded from the shape of the first embodiment shown in FIG.
FIG. 10 shows a sectional view of the intake valve portion A when the intake valve stopper 32 shown in FIG. 9 is assembled. The vertical section is shown in the upper section and the 45-degree section is shown in the lower section. The plurality of fixing portions 32c are configured to be located on the pressurizing chamber side with respect to the suction valve side surface of the overlapping portion 32d, and the outer peripheral side surface of the overlapping portion 32d and the suction valve side surface of the plurality of fixing portions 32c are formed. Then, the first flow path 32e is formed, and the second flow path 32f that connects the first flow path 32e and the pressurizing chamber 11 is formed between the adjacent fixing portions 32c. Then, the plurality of fixing portions 32c are positioned so as to overlap the inner peripheral side surfaces of the plurality of fixing portions 32c in the intake valve axial direction, and a space 32g is formed on the pressurizing chamber side with respect to the pressurizing chamber side surface of the overlapping portion 32d. The space 32g is formed so as to form a part of the second flow path 32f.
By doing so, the second flow path 32f is expanded in the radial direction beyond the projected area viewed from the axial direction, and a larger flow path cross-sectional area can be secured with a simple structure, which is advantageous for reducing pressure loss. Is.

Further, in forming these shapes, a plurality of fixing portions 32c are formed by a press manufacturing method or a forging manufacturing method so as to be extruded toward the pressurizing chamber in the axial direction with respect to the overlapping portion 32d. Is arranged closer to the pressurizing chamber than the surface of the overlapping portion 32d on the pressurizing chamber side. Alternatively, the plurality of fixing portions 32c are configured such that almost all of the fixing portions 32c are arranged closer to the pressurizing chamber than the most pressurizing chamber side end of the surface of the overlapping portion 32d on the pressurizing chamber side in the axial direction of the intake valve.
By doing so, it is possible to form a plurality of fixing portions 32c and spaces 32g at the same time as forming the flow path, and it is possible to reduce the number of processing steps.
Further, similarly to the case of the first embodiment, the suction valve stopper 32 may be provided with the spring holding portion 32h. In that case, the overlapping portion 32d has a recessed portion 32j that is recessed toward the pressurizing chamber on the inner peripheral side, and holds the spring 33 that biases the intake valve 30 in the valve closing direction in the recessed portion 32j. The end of the recess 32j that is formed closest to the pressurizing chamber and the end of the fixed part 32c that is closest to the pressurizing chamber are substantially the same in the axial direction of the intake valve. It is formed at a position, or the end of the recess is located closer to the pressurizing chamber than the end of the fixed part.
By doing so, the suction valve stopper can be integrated with a plurality of functions and the structure can be simplified, and the recessed portion 32j is formed at the same time as the flow passage is formed by the press manufacturing method or the forging manufacturing method, thereby reducing the number of processing steps. Can be reduced, which is advantageous from the viewpoint of cost reduction.

  In general, if the configuration of this embodiment is used, a simple structure with a small number of processing steps ensures a larger flow passage cross-sectional area than that of the first embodiment, and a pressure loss occurs even when the discharge fuel has a large flow rate. It is possible to provide an intake valve that prevents increase and realizes highly accurate flow rate control, and a low-cost fuel supply pump to which the intake valve is applied.

  Although all the explanations are finished above, the present invention is not limited to the above-described embodiments, and various modifications are included. For example, the embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those including all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add / delete / replace other configurations with respect to a part of the configurations of the respective embodiments.

1: Pump main body 2: Plunger 6: Cylinder 7: Seal holder 8: Discharge valve mechanism 9: Pressure pulsation reduction mechanism 10a: Low pressure fuel inlet 11: Pressurization chamber 12: Fuel outlet 13: Plunger seal 27: Engine control unit (Control unit)
30: Suction valve 31: Suction valve seat 32: Suction valve stopper 33: Suction valve spring 35: Rod 36: Anchor part 38: Outer core 39: Fixed core 40: Rod biasing spring 41: Anchor part biasing spring 43: Electromagnetic coil

Claims (12)

In a fuel supply pump including a pump body in which a pressurizing chamber is formed and an intake valve arranged on the intake side of the pressurizing chamber,
An overlapping portion that is arranged between the pressurizing chamber and the suction valve and that overlaps the suction valve in the suction valve axial direction, and is formed integrally with the overlapping portion on the outer peripheral side of the outer peripheral side surface of the overlapping portion, A plurality of fixing portions for fixing the overlapping portion,
A first flow path is formed between an outer peripheral side surface of the overlapping part and a housing part arranged further outside than the outer peripheral side surface of the overlapping part, and the first flow path is a pressurizing chamber side surface of the overlapping part. Is connected to the second flow path on the pressurizing chamber side, and the first flow path and the second flow path are formed so as to be continuously connected to the housing portion ,
The fuel supply pump in which the first flow path is formed in an annular shape on the outer peripheral side of the overlapping portion, and the second flow path is formed between the fixed portion and the housing portion that are adjacent to each other . In a fuel supply pump including a pump body in which a pressurizing chamber is formed and an intake valve arranged on the intake side of the pressurizing chamber,
An overlapping portion that is arranged between the pressurizing chamber and the suction valve and that overlaps the suction valve in the suction valve axial direction, and is formed integrally with the overlapping portion on the outer peripheral side of the outer peripheral side surface of the overlapping portion, A plurality of fixing portions for fixing the overlapping portion,
A first flow path is formed between an outer peripheral side surface of the overlapping part and a housing part arranged further outside than the outer peripheral side surface of the overlapping part, and the first flow path is a pressurizing chamber side surface of the overlapping part. Is connected to the second flow path on the pressurizing chamber side, and the first flow path and the second flow path are formed so as to be continuously connected to the housing portion,
The thickness of the plurality of fixing portions in the intake valve axial direction is configured to be smaller than the thickness of the overlapping portion in the suction valve axial direction, and the surfaces of the plurality of fixing portions on the pressurizing chamber side are the overlapping portions. Supply pump configured so as to be located on the suction valve side of the surface of the pressurizing chamber side of the section. The fuel supply pump according to claim 1 ,
The fuel supply pump in which the plurality of fixing portions are arranged closer to the pressurizing chamber than a surface of the overlapping portion on the pressurizing chamber side. The fuel supply pump according to claim 1 ,
In the suction valve axial direction, almost all of the plurality of fixing portions are arranged closer to the pressurizing chamber than the end portion of the overlapping portion on the pressurizing chamber side closer to the most pressurizing chamber. The fuel supply pump according to claim 1 ,
The fuel supply pump, wherein the overlapping portion is a suction valve stopper that restricts movement of the suction valve in the opening direction. The fuel supply pump according to claim 1 ,
The fuel supply pump, wherein the overlapping portion includes a spring holding portion that holds a spring that biases the intake valve in a valve closing direction. The fuel supply pump according to claim 1 ,
The plurality of fixing portions are arranged at predetermined intervals in the circumferential direction on the outer peripheral side of the outermost peripheral end portion of the outer peripheral side surface of the overlapping portion,
The fuel supply pump in which the second flow path is formed on the outer peripheral side of the outermost peripheral end of the outer peripheral side surface of the overlapping portion. The fuel supply pump according to claim 1 ,
The plurality of fixing portions are arranged closer to the pressure chamber than the pressure chamber side surface of the overlapping portion, and the overlapping portion is located at a position overlapping the inner circumferential surface of the plurality of fixing portions in the intake valve axial direction. A fuel supply pump in which a space is formed on the pressurizing chamber side of the pressurizing chamber side and the space is formed to communicate with the second flow path. The fuel supply pump according to claim 1 ,
The fuel supply pump in which the overlapping portion and the plurality of fixing portions are formed of press parts or forged parts. The fuel supply pump according to claim 1 ,
The plurality of fixing portions are fuel supply pumps having press-fitting portions on the outer peripheral side that are press-fitted into holes formed in the pump body. The fuel supply pump according to claim 1 ,
A fuel supply pump configured such that an outermost peripheral end portion of an outer peripheral side surface of the overlapping portion is located closer to an outer peripheral side than an outermost peripheral end portion of an outer peripheral surface of the intake valve. In a fuel supply pump including a pump body in which a pressurizing chamber is formed and an intake valve arranged on the intake side of the pressurizing chamber,
An overlapping portion that is arranged between the pressurizing chamber and the suction valve and that overlaps the suction valve in the suction valve axial direction, and is formed integrally with the overlapping portion on the outer peripheral side of the outer peripheral side surface of the overlapping portion, A plurality of fixing portions for fixing the overlapping portion,
A first flow path is formed between an outer peripheral side surface of the overlapping part and a housing part arranged further outside than the outer peripheral side surface of the overlapping part, and the first flow path is a pressurizing chamber side surface of the overlapping part. Is connected to the second flow path on the pressurizing chamber side, and the first flow path and the second flow path are formed so as to be continuously connected to the housing portion,
The overlapping portion has a recessed portion that is recessed toward the pressurizing chamber on the inner peripheral side, and holds a spring that biases the intake valve in the valve closing direction in the recessed portion,
The end of the recessed portion formed closest to the pressurizing chamber in the recessed portion and the end of the fixed portion formed closest to the pressurizing chamber of the plurality of fixed portions are formed at substantially the same position in the axial direction of the intake valve. Or a fuel supply pump formed such that the end of the recessed portion is located closer to the pressurizing chamber than the end of the fixed portion.

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