JP2010174751A - Fuel supply pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply pump constructed without putting a stopper regulating an open valve position between a valve body and a cylinder body. <P>SOLUTION: The fuel supply pump includes a cylinder body 11 including a pressurizing chamber 113 pressurizing fuel by reciprocating movement of a plunger to an opening end side of a slide hole, and a solenoid valve opening and closing a valve hole 36 communicating to the pressurizing chamber 113. The solenoid valve includes a through hole 31 providing communication between the pressurizing chamber 113 and an opposite side of the pressurizing chamber 113, a valve body 3 having a seat surface 34 facing the pressurizing chamber 113 formed thereon, a valve element 4 including a seat part 42 sliding in the through hole 31 in such a manner that the same can freely reciprocate in the through hole 31 and opening and closing the valve hole 36 by being separated from and seated on the seat surface 34, and a stopper 43 cooperating with the valve element 4 and regulating a valve open position of the valve element 4 by abutting on an end surface 35 at an opposite side of the pressurizing chamber 113 out of end surfaces at opening end side of the through hole 31 in the valve body 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel supply pump, and is suitably applied to a fuel supply pump that supplies high-pressure fuel corresponding to a fuel injection pressure in a fuel injection device of a diesel engine, for example.

  2. Description of the Related Art Conventionally, as a fuel supply pump, a slide hole in which a plunger slides in a reciprocating manner is provided inside, and a pressurization chamber in which fuel is sucked and pressurized by a reciprocating movement of the plunger at the opening end side of the slide hole. A cylinder body and an electromagnetic valve that faces the pressurizing chamber and opens and closes a valve hole that communicates with the pressurizing chamber are known (see Patent Document 1).

  In such a fuel supply pump, fuel is sucked into the pressurizing chamber by lowering the plunger when the solenoid valve is opened, and fuel in the pressurizing chamber is pressurized by raising the plunger when the solenoid valve is closed. The Here, between the valve body and the cylinder body of the solenoid valve, a flat plate-shaped stopper that restricts the valve opening position of the solenoid valve is interposed. This stopper is held and fixed by the tightening axial force in the central axis direction generated when the solenoid valve is fastened and fixed to the cylinder body (screw fastening) in a state of being sandwiched between the valve body and the cylinder body. . The contact surface between the valve body and the stopper and the contact surface between the cylinder body and the stopper are configured to have a sealing property against high-pressure fuel.

Japanese Patent Laid-Open No. 3-219178

  In the above-described conventional fuel supply pump, when the plunger is raised when the solenoid valve is closed and the fuel in the pressurizing chamber is pressurized to increase the internal pressure in the pressurizing chamber, the cylinder body having a large pressure receiving area that receives the internal pressure is Although it is deformed to the outside, the flat plate structure stopper hardly deforms. Further, the axial pressure of the solenoid valve against the cylinder body is canceled and reduced by the internal pressure, so that the frictional force between the cylinder body and the stopper decreases. For this reason, relative slip occurs between the cylinder body and the stopper.

  On the other hand, if the plunger is lowered when the solenoid valve is opened, the internal pressure in the pressurizing chamber decreases, and the deformation of the cylinder body when the internal pressure in the pressurizing chamber is high tends to return to the original. Relative slip in the opposite direction to that described above occurs. By repeating these relative slips, there is a concern that so-called fretting wear occurs on the contact surface between the cylinder body and the stopper, and the sealing performance of the contact surface decreases.

  Similarly, there is a concern that the sealing performance of the contact surface between the valve body and the stopper is lowered.

  Such a problem occurs because a stopper is interposed between the valve body and the cylinder body of the solenoid valve, and the stopper is not interposed between the valve body and the cylinder body. It will be solved.

  The present invention has been made in view of such circumstances, and provides a fuel supply pump configured such that a stopper for regulating the opening position of the solenoid valve is not interposed between the valve body and the cylinder body of the solenoid valve. The purpose is to do.

  In order to achieve the above object, the present invention comprises the following technical means.

  According to the first aspect of the present invention, there is provided a fuel supply pump for supplying high-pressure fuel to an internal combustion engine, and a sliding hole in which a plunger slides in a reciprocating manner, and an opening end side of the sliding hole. A cylinder body having a pressurizing chamber in which fuel is sucked and pressurized by a reciprocating movement of the plunger, and an electromagnetic valve arranged facing the pressurizing chamber and opening and closing a valve hole communicating with the pressurizing chamber; The solenoid valve is a valve body that forms a pressurizing chamber together with the end face of the plunger and the inner peripheral surface of the sliding hole, and has a through-hole communicating with the opposite side of the pressurizing chamber and the pressurizing chamber. A valve body having a seat surface facing the chamber, a valve body having a seat portion that slides in and through the through-hole so as to reciprocate and opens and closes the valve hole, and a valve body; This is a cooperating stopper that is located on the opening end side of the through hole in the valve body. Characterized in that it comprises a stopper for defining the open position of the pressure chamber opposite the end face abutment to be in the valve body of the surfaces, the.

  According to this configuration, the stopper which regulates the valve opening position of the valve body by co-operating with the valve body and abutting with the end surface on the opposite side of the pressurizing chamber of the end surface on the opening end side of the through hole in the valve body. Provided. For this reason, the stopper which controls the valve opening position of the valve body of a solenoid valve can be comprised without interposing between the valve body and cylinder body of a solenoid valve.

  According to the invention described in claim 2, the electromagnetic valve includes a spring that urges the valve body in the valve opening direction, and a solenoid unit that electromagnetically drives the valve body in the valve closing direction against the urging force of the spring. And an armature that cooperates with the valve body and is electromagnetically attracted by the solenoid portion, and the stopper is formed integrally with the armature.

  According to this configuration, since the stopper is formed integrally with the armature, the stopper can be configured without newly increasing the number of parts and not being interposed between the valve body and the cylinder body of the solenoid valve.

  According to a third aspect of the present invention, the stopper is made of a high hardness material.

  According to this configuration, since the stopper is formed of a high hardness material, it is possible to prevent wear due to collision with the valve body when the valve is opened, and to suppress a change in the movement amount (valve lift) of the valve body. it can. Therefore, the stopper which can suppress the change of the moving amount | distance of a valve body can be comprised without interposing between the valve body of a solenoid valve, and a cylinder body.

It is sectional drawing which shows the fuel supply pump by one Embodiment of this invention. It is an enlarged view of the II section in FIG. It is an enlarged view of the III section in FIG. It is an enlarged view which shows the modification of FIG. It is an enlarged view which shows the modification of FIG.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, taking as an example a fuel supply pump used in a vehicle common rail fuel injection device. In addition, the same code | symbol is attached | subjected to the mutually same or equivalent part in a figure.

(Constitution)
The common rail fuel injection device for a vehicle mainly includes a fuel tank, a fuel supply pump 10 shown in FIG. 1, a common rail (not shown), and a fuel injection valve. The high-pressure fuel supplied from the fuel supply pump 10 is accumulated in the common rail, and the high-pressure fuel in the common rail is distributed to the fuel injection valves provided in each cylinder of the internal combustion engine. Injected into the chamber.

  The fuel tank stores normal pressure fuel, and the fuel supply pump 10 sucks normal pressure fuel from the fuel tank via a feed pump (not shown), pressurizes the fuel, and pumps the fuel to the common rail. Supply high-pressure fuel to The fuel supply pump 10 includes a solenoid valve 1, a cylinder body 11 that houses a plunger 12 therein, and a pump housing 14 that houses a camshaft 13 therein.

  The pump housing 14 rotatably supports a camshaft 13 that is rotationally driven by an engine crankshaft. A cam 131 having three cam peaks is integrally assembled on the outer periphery of the camshaft 13. A tappet 122 that slides in the illustrated vertical direction is disposed in the pump housing 14, and a roller 124 that supports the pin 123 and is rotatable is disposed at the lower portion of the tappet 122. The tappet 122 is always urged downward in the figure by the urging force of the coiled spring 121. Thereby, the roller 124 is always in contact with the outer peripheral surface of the cam 131.

  The cylinder body 11 is fitted in the pump housing 14 in a fluid-tight manner, and the cylinder body 11 is provided with fuel passages 112 and 114, a sliding hole 111, and a pressurizing chamber 113. The fuel passage 112 is a fuel passage through which low pressure fuel is introduced from the feed pump, and the sliding hole 111 is a sliding hole through which the plunger 12 slides in a reciprocating manner in the vertical direction in the figure. The lower end portion of the plunger 12 shown in the figure is fixed to an annular plate-shaped spring receiver 125 and is in contact with the upper end surface of the tappet 122 shown in the drawing.

  The pressurizing chamber 113 is provided on the opening end side of the upper side of the sliding hole 111 in the drawing, and the fuel is sucked into the pressurizing chamber 113 through the fuel passage 112 and the electromagnetic valve 1 by the reciprocating movement of the plunger 12. Pressurized. The fuel passage 114 is a fuel passage through which high-pressure fuel is introduced from the pressurizing chamber 113 and supplies the high-pressure fuel to the common rail. The fuel pressurized as the internal volume of the pressurizing chamber 113 expands and contracts with the reciprocating movement of the plunger 12 is configured to be pressure-fed and supplied from the pressurizing chamber 113 to the common rail via the fuel passage 114. Yes. As shown in FIG. 2, a female screw portion 115 to which a male screw portion 21 of the valve housing 2 described later is screwed is formed on the inner periphery of the cylinder body 11.

  The solenoid valve 1 is arranged facing the pressurizing chamber 113, and is a normally open type that controls the amount of fuel supplied from the fuel supply pump 10 by opening and closing a valve hole 36 (FIG. 3) communicating with the pressurizing chamber 113. It is a normally open type) electromagnetic control valve. The electromagnetic valve 1 includes a valve housing 2 that houses a solenoid portion 5 and a spring 6 inside, and a valve body 3 that houses a valve body 4 inside.

  On the outer periphery of the valve housing 2, a male screw portion 21 for fastening the electromagnetic valve 1 to the female screw portion 115 of the cylinder body 11 is formed. The screw tightening is performed with a predetermined tightening axial force so that the flat surface 33 of the valve body 3 and the flat surface 116 of the cylinder body 11 are brought into close contact with each other. In this manner, the flat surfaces 33 and 116 are directly brought into close contact with each other, thereby preventing fuel leakage from the pressurizing chamber 113 to the outside. An O-ring for preventing leakage of fuel to the outside is mounted between the outer peripheral surface of the valve housing 2 and the inner peripheral surface of the cylinder body 11.

  The coiled spring 6 urges the valve body 4 in the downward direction, which is the valve opening direction, and the solenoid unit 5 is in the valve closing direction against the urging force of the spring 6. It is electromagnetically driven upward in the figure. The solenoid unit 5 includes a solenoid coil 51 and a stator 52, and when the solenoid coil 51 is energized, the stator 52 attracts the armature 41 made of a magnetic body that cooperates with the valve body 4 by electromagnetic force.

  The valve body 3 is formed in a predetermined shape from a metal material, and is fixed to the distal end side (the lower end side in the drawing) of the valve housing 2 by caulking or the like. The valve body 3 forms a pressurizing chamber 113 together with the end surface 120 of the plunger 12 and the inner peripheral surface of the sliding hole 111. The valve body 3 is formed with a through hole 31, a fuel passage 32, and a seat surface 34 shown in FIG. The through-hole 31 is a through-hole communicating with the pressurizing chamber 113 on the opposite side (the upper side with respect to the pressurizing chamber 113) and the pressurizing chamber 113, and the valve body 4 can reciprocate in the vertical direction in the figure. A sliding hole that slides. The fuel passage 32 is a fuel passage communicating with the fuel passage 112, and the seat surface 34 is disposed so as to face the pressurizing chamber 113.

  A seat portion 42 is formed on the valve body 4 and an armature 41 is attached thereto. The seat portion 42 is separated from the seat surface 34 to open and close the valve hole 36, and the valve hole 36 is formed as a gap between the seat portion 42 and the seat surface 34. Therefore, when the solenoid coil 51 is not energized, the seat portion 42 is separated from the seat surface 34 by the biasing force of the spring 6, and the valve hole 36 is opened. That is, the solenoid valve 1 is a normally open type in which the valve hole 36 is opened without energizing the solenoid coil 51.

  When the solenoid coil 51 is energized, the seat portion 42 is seated on the seat surface 34 against the biasing force of the spring 6 and the valve hole 36 is closed.

  The basic configuration of the fuel supply pump 10 has been described above. Hereinafter, a characteristic configuration of the fuel supply pump 10 will be described.

(Characteristic configuration)
The valve body 4 is further provided with a stopper 43 on the inner peripheral side of the armature 41. The stopper 43 co-operates with the valve body 4 and is an end face on the opposite side of the pressurizing chamber 113 from the end face (the end face on the seat face 34 side and the stopper face 35) of the through hole 31 in the valve body 3. It is a stopper that regulates the valve opening position of the valve body 4 by coming into contact with a certain stopper surface 35.

  The stopper 43 is formed in an annular shape with a high hardness material such as tool steel, hardened steel of stainless steel, carburized steel of chrome molybdenum steel, and is press-fitted into the valve body 4 and attached to the valve body 4. The armature 41 is pressed into a stopper 43 attached to the valve body 4 and attached to the valve body 4. In addition, after press-fitting the stopper 43 into the armature 41, it is also possible to press-fit into the valve body 4 and attach it to the valve body 4.

  The illustrated lower end portion of the stopper 43 protrudes below the illustrated lower end portion of the armature 41, and the valve opening position of the valve body 4 is defined by the stopper 43 coming into contact with the stopper surface 35. That is, the movement amount (valve lift) of the valve body 4 is the distance between the valve closing position where the seat portion 42 is seated on the seat surface 34 and the valve opening position where the stopper 43 contacts the stopper surface 35. For this valve lift adjustment, the press-fitting position of the stopper 43 with respect to the valve body 4 is adjusted and press-fitted.

  Note that the outer diameter of the stopper 43 is set to the same size as the inner diameter of the stator 52 so that the attracting force by which the stator 52 attracts the armature 41 by the electromagnetic force by energizing the solenoid coil 51 is not reduced by the stopper 43. ing. That is, a portion where the armature 41 is reduced due to the presence of the stopper 43 is a portion that does not face the stator 52.

(Function and effect)
Next, the operation of the fuel supply pump 10 of the present embodiment will be described based on FIGS.

  When the camshaft 13 of the fuel supply pump 10 is driven and rotated by the crankshaft of the engine, the tappet 122 and the roller 124 reciprocate integrally along the outer peripheral surface of the cam 131 in the illustrated vertical direction. When the tappet 122 reciprocates in the vertical direction in the figure, the plunger 12 also reciprocates in the vertical direction in the figure in conjunction with the tappet 122. At this time, energization to the solenoid coil of the solenoid valve 1 is stopped, and the magnetomotive force of the solenoid coil 51 is demagnetized, so that the valve element 4 is opened by the biasing force of the spring 6 (the stopper 43 is the stopper surface). 35). Thereby, the valve hole 36 (the gap between the seat portion 42 and the seat surface 34) is opened by the valve body 4. Further, when the plunger 12 descends in the sliding hole 111 of the cylinder body 11, the internal volume in the pressurizing chamber 113 increases. As a result, the fuel is introduced into the pressurizing chamber 113 through the fuel passages 112 and 32 and the valve hole 36 (the gap between the seat portion 42 and the seat surface 34) as the plunger 12 descends.

  When energization to the solenoid coil 51 of the solenoid valve 1 is performed at the timing when the plunger 12 moves from the lowering to the rising in the sliding hole 111 of the cylinder body 11, a magnetomotive force is generated in the solenoid coil 51. A plurality of magnetic bodies such as the armature 41 and the stator 52 are magnetized. As a result, the armature 41 is attracted by the stator 52, the valve body 4 moves in the valve closing direction, and the seat portion 42 of the valve body 4 is seated on the seat surface 34 of the valve body 3. Thereby, the valve hole 36 of the electromagnetic valve 1 is closed by the valve body 4. When the plunger 12 further moves up in the sliding hole 111 of the cylinder body 11, the internal volume in the pressurizing chamber 113 becomes narrower. As a result, the fuel introduced into the pressurizing chamber 113 is pressurized and pressurized as the plunger 12 rises. At this time, when the fuel pressure in the pressurizing chamber 113 becomes higher than the opening pressure of the discharge valve, the discharge valve is opened, and high pressure fuel is pumped from the pressurizing chamber 113 to the common rail via the fuel passage 114. The After the high pressure fuel is pumped, the energization of the solenoid coil 51 of the solenoid valve 1 is stopped, the valve body 4 returns to the valve open position, and the fuel is sucked into the pressurizing chamber 113 again.

  In the solenoid valve 1 of the fuel supply pump 10 according to the present embodiment, as a characteristic configuration, the valve body 3 and the valve body 3 have an end surface on the opening end side of the through hole 31 (an end surface on the seat surface 34 side and a stopper surface). 35), a stopper 43 that defines the valve opening position of the valve body 4 by contacting the stopper surface 35 that is the end surface opposite to the pressurizing chamber 113 is provided. For this reason, the stopper which controls the valve opening position of the valve body 4 of the solenoid valve 1 can be configured without being interposed between the valve body 3 and the cylinder body 11 of the solenoid valve 1.

  Accordingly, it is possible to solve the problem of deterioration of the sealing performance on the contact surface between the cylinder body and the stopper and the contact surface between the valve body and the stopper by interposing the stopper between the valve body and the cylinder body of the solenoid valve.

  In the present embodiment, the flat surface 33 of the valve body 3 and the flat surface 116 of the cylinder body 11 are in direct contact with each other. For this reason, when the electromagnetic valve 1 is closed (when the seat portion 42 is seated on the seat surface 34), the plunger 12 rises and the fuel in the pressurizing chamber 113 is pressurized, and the inside of the pressurizing chamber 113 is Even if the internal pressure increases, both the pressure receiving area of the cylinder body 11 and the pressure receiving area of the valve body 3 are large, so that both the cylinder body 11 and the valve body 3 are deformed outward. As a result, fretting wear due to relative sliding at the close contact portions of the flat surfaces 33 and 116 can be suppressed, and deterioration of the sealing performance at the close contact portions can be suppressed.

  Further, since the stopper 43 is formed of a high hardness material, it is possible to prevent wear of the stopper 43 due to a collision with the stopper surface 35 of the valve body 3 when the solenoid valve 1 is opened, and the amount of movement of the valve body 4 Changes in (valve lift) can be suppressed.

  Further, since the outer diameter of the stopper 43 is set to the same size as the inner diameter of the stator 52, it is possible to suppress the attraction force that the stator 52 attracts the armature 41 by the electromagnetic force from being reduced by the stopper 43.

(Modification)
In the above example, the flat surface 33 of the valve body 3 and the flat surface 116 of the cylinder body 11 are brought into close contact with each other. However, as shown in FIG. 4, the gasket 7 can be interposed between the flat surfaces 33 and 116. Accordingly, fretting wear due to relative slip at the close contact portions of the flat surfaces 33 and 116 can be surely eliminated, so that a decrease in sealing performance at the close contact portions can be more reliably suppressed.

  In the above-described example, the stopper 43 is press-fitted and attached to the valve body 4, but is not limited thereto. If the stopper 43 is formed of a material whose hardness is increased by carburizing, the carbon content of the stopper 43 can be reduced. For this reason, it becomes possible to join the stopper 43 to the valve body 4 by welding.

  In the above example, the stopper 43 is formed separately from the valve body 4 and the armature 41. However, as shown in FIG. 5, the stopper 431 is formed as a hard film on the armature 411, and the stopper 431 is formed as the armature 411. And can be formed integrally. In the armature 411, a portion where the stopper 431 is formed is formed so as to protrude below the lower end portion of the remaining portion in the figure, and the stopper 431 is formed in the portion protruding below.

  The stopper 431 is formed on the armature 411 by a CVD method (chemical film formation method) or a PVD method (physical film formation method) as a hard film such as titanium or silicon nitride such as TiN or TiC. For this reason, since the stopper 431 is integrally formed with the armature 411, the stopper 431 is not interposed between the valve body 3 and the cylinder body 11 of the solenoid valve 1 without newly increasing the number of parts. it can.

DESCRIPTION OF SYMBOLS 10 Fuel supply pump, 1 Solenoid valve, 2 Valve housing, 21 Male thread part 3 Valve body, 31 Through hole, 32 Fuel passage, 33 Plane, 34 Seat surface 35 Stopper surface, 36 Valve hole, 4 Valve body, 41,411 Armature 42 Seat part, 43, 431 Stopper, 5 Solenoid part 51 Solenoid coil, 52 Stator, 6 Spring 7 Gasket, 11 Cylinder body, 111 Sliding hole, 112 Fuel path 113 Pressurizing chamber, 114 Fuel path, 115 Female thread part, 116 Planar 12 Plunger, 120 End face, 121 Spring, 122 Tappet 123 Pin, 124 Roller, 125 Spring support, 13 Camshaft 131 Cam, 14 Pump housing

Claims (3)

A fuel supply pump for supplying high pressure fuel to an internal combustion engine,
A cylinder body having a sliding hole in which the plunger slides in a reciprocating manner inside, and a pressure chamber in which fuel is sucked and pressurized by the reciprocating movement of the plunger on the opening end side of the sliding hole;
An electromagnetic valve arranged facing the pressurizing chamber and opening and closing a valve hole communicating with the pressurizing chamber;
The solenoid valve is
A valve body that forms the pressurizing chamber together with the end surface of the plunger and the inner peripheral surface of the sliding hole, and has a through hole communicating with the opposite side of the pressurizing chamber and the pressurizing chamber, A valve body having a seat surface facing the pressurizing chamber;
A valve body having a seat portion that slides in and through the through-hole so as to freely reciprocate and opens and closes the valve hole by being attached to and detached from the seat surface;
A stopper that cooperates with the valve body, and in the valve body, a valve opening position of the valve body is defined by abutting with an end surface on the opposite side of the pressurizing chamber of the end surface on the opening end side of the through hole. And a fuel supply pump. The solenoid valve includes a spring that biases the valve body in a valve opening direction, a solenoid unit that electromagnetically drives the valve body in a valve closing direction against a biasing force of the spring, and the valve body. An armature that moves and is electromagnetically attracted by the solenoid part,
The fuel supply pump according to claim 1, wherein the stopper is formed integrally with the armature.   The fuel supply pump according to claim 1, wherein the stopper is made of a high hardness material.

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