Abstract:
The purpose of the present invention is to provide a fuel injection pump  1  wherein it is possible to easily position the second fuel supply path  21   b  of a housing  21  with the fuel supply hole  22   a  functioning as the fuel path of an insert piece  22 , and to secure the insert piece  22  such that same does not rotate within the housing  21 . The fuel injection pump  1  is provided with an electromagnetic spill valve  20 , wherein the electromagnetic spill valve  20  is equipped with: the housing  21  on which an insert piece hole  21   d  is formed; the insert piece  22  which is formed in a roughly cylindrical shape having a valve seat  22   b  on the inner circumferential surface and which is inserted into the insert piece hole  21   d  in a detachable manner; a spill valve body  23  which is formed on the outer circumferential surface in a roughly columnar shape having a seal surface  23   b  capable of seating on the valve seat  22   b , and which is inserted into the insert piece  22  in a slidable manner; and a securing means securing hole  21   h , notched part  22   h , securing screw  26  for securing the position of the insert piece in the periphery of the axial center relative to the insert piece hole  21   d.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an art of a fuel injection pump provided in a diesel engine. 
       BACKGROUND ART 
       [0002]    Conventionally, a fuel injection pump provided in a large diesel engine is known in which timing of fuel injection and number of fuel injection are controlled corresponding to driving state of the engine so as to improve fuel efficiency and to reduce exhaust gas emission. In the fuel injection pump, an electromagnetic spill valve is opened and closed in optional timing so as to perform fuel injection with high accuracy. 
         [0003]    In the fuel injection pump, a spill valve body of the electromagnetic spill valve is opened and closed corresponding to driving state of the engine intricately and rapidly, whereby large shock and big friction are caused continuously when a sealing surface of the spill valve body is seated on a valve seat formed in a housing of the electromagnetic spill valve. Accordingly, for improving wear resistance of the sealing surface and the valve seat, the whole spill valve body and housing must be configured by materials with high intensity, thereby increasing a production cost. 
         [0004]    Then, an art is proposed that a valve seat sleeve (insert piece) having a spill valve body (valve body) and a valve seat (valve seat part) is formed by materials with high intensity and press-inserted into a housing formed by normal materials so as to improve wear resistance and suppress increase of a production cost. For example, an art of the Patent Literature 1 is so. 
         [0005]    However, in the art disclosed in the Patent Literature 1, when the insert piece is not press-inserted at a suitable position, or when processing accuracy of the housing or the insert piece is not suitable so that the insert piece is moved in the housing, a fuel path formed in the housing may not be communicated with a fuel path formed in the insert piece, thereby cutting off the fuel paths. 
       PRIOR ART REFERENCE 
     Patent Literature 
       [0000]    
       
         Patent Literature 1: the Japanese Patent Laid Open Gazette Hei. 11-294297 
       
     
       DISCLOSURE OF INVENTION 
     Problems to Be Solved by the Invention 
       [0007]    The present invention is provided in consideration of the conditions as mentioned above, and the purpose of the invention is to provide a fuel injection pump in which a position of a fuel path of a housing can be matched easily to a position of a fuel path of an insert piece and the insert piece can be secured in the housing so as not to be rotatable. 
       Means for Solving the Problems 
       [0008]    According to the present invention, in a fuel injection pump having an electromagnetic spill valve, the electromagnetic spill valve includes a housing in which an insert piece hole is formed, an insert piece formed substantially like a cylinder whose inner peripheral surface is provided therein with a valve seat and inserted detachably into the insert piece hole, a spill valve body formed substantially like a cylinder whose outer peripheral surface is provided therein with a seal surface which can be seated on the valve seat and inserted slidably into the insert piece, and a securing means securing a position of the insert piece concerning the insert piece hole around an axis. 
         [0009]    According to the present invention, the securing means includes a securing hole communicated with the insert piece hole from a side surface of the housing, a notched part formed in an outer peripheral surface of the insert piece facing the securing hole, and a securing member inserted into the securing hole and the notched part. 
         [0010]    According to the present invention, the securing means includes a housing side notched part formed in an inner peripheral surface of the insert piece hole, an insert piece side notched part formed in an outer peripheral surface of the insert piece facing the housing side notched part, a securing member inserted into the housing side notched part and the insert piece side notched part, and a sealing member sealing the insert piece and the securing member to an inside of the housing. 
         [0011]    According to the present invention, the securing means includes a housing side flat surface part formed in an inner peripheral surface of the insert piece hole, and an insert piece side flat surface part formed in an outer peripheral surface of the insert piece facing the housing side flat surface part. 
       Effect of the Invention 
       [0012]    The present invention configured as the above brings the following effects. 
         [0013]    According to the present invention, the insert piece can be attached to the housing while being rotatable in the insert piece hole. Accordingly, a position of the fuel path of the housing can be matched easily to a position of the fuel path of the insert piece, and the insert piece can be secured in the housing by the securing means so as not to be rotatable. 
         [0014]    According to the present invention, the insert piece is secured to a predetermined position of the housing by the securing member. Accordingly, a position of the fuel path of the housing can be matched easily to a position of the fuel path of the insert piece, and the insert piece can be secured in the housing by the securing means so as not to be rotatable. 
         [0015]    According to the present invention, the insert piece is secured by the securing means configured between the insert piece hole and the insert piece. Accordingly, the securing means is sealed in an inside of the housing and is not exposed outside, whereby oil leak from the securing means can be prevented. A position of the fuel path of the housing can be matched easily to a position of the fuel path of the insert piece, and the insert piece can be secured in the housing by the securing means so as not to be rotatable. 
         [0016]    According to the present invention, the insert piece is secured to a predetermined position of the housing without any securing member. Accordingly, it is not necessary to provide the securing member, whereby number of assembly processes can be reduced. A position of the fuel path of the housing can be matched easily to a position of the fuel path of the insert piece, and the insert piece can be secured in the housing by the securing means so as not to be rotatable. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIG. 1  is a sectional view of a part of a fuel injection pump according to a first embodiment of the present invention. 
           [0018]      FIG. 2(   a ) is an enlarged sectional view of an electromagnetic spill valve part of a fuel injection pump according to a second embodiment of the present invention.  FIG. 2(   b ) is an arrow sectional view of the line C-C in  FIG. 2(   a ). 
           [0019]      FIG. 3(   a ) is an enlarged sectional view of an electromagnetic spill valve part of the fuel injection pump according to the first embodiment of the present invention which shows flow of fuel when the electromagnetic spill valve is closed.  FIG. 3(   b ) is an enlarged sectional view of the electromagnetic spill valve part of the fuel injection pump according to the first embodiment of the present invention which shows the flow of fuel when the electromagnetic spill valve is opened. 
           [0020]      FIG. 4(   a ) is an enlarged sectional view of the electromagnetic spill valve part of the fuel injection pump according to the second embodiment of the present invention.  FIG. 4(   b ) is an arrow sectional view of the line D-D in  FIG. 4(   a ). 
           [0021]      FIG. 5(   a ) is an enlarged sectional view of an electromagnetic spill valve part of a fuel injection pump according to a third embodiment of the present invention.  FIG. 5(   b ) is a perspective view of an insert piece according to the third embodiment of the present invention.  FIG. 5(   c ) is an arrow sectional view of the line E-E in  FIG. 5(   a ). 
           [0022]      FIG. 6(   a ) is an enlarged sectional view of an electromagnetic spill valve part of a fuel injection pump of another embodiment.  FIG. 6(   b ) is perspective view of an insert piece of this embodiment.  FIG. 6(   c ) is an arrow sectional view of the line F-F in  FIG. 6(   a ). 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Next, an explanation will be given on a fuel injection pump  1  which is a first embodiment of the present invention referring to  FIGS. 1 and 2 . Herein, a direction of an arrow A is regarded as an upward direction so as to define the vertical direction, and a direction of an arrow B is regarded as a rightward direction so as to define the lateral direction. 
         [0024]    As shown in  FIG. 1 , the fuel injection pump  1  is connected to a low pressure pump (feed pump) (not shown), and pressurizes fuel from the low pressure pump and supplies the fuel to a fuel injection nozzle (not shown). The fuel injection pump  1  has a pump body part  10 , an electromagnetic spill valve  20  and a two-way delivery valve part  30 . 
         [0025]    The pump body part  10  includes a pump body upper part  11 , a barrel  12 , a plunger  13 , a plunger spring  14 , a tappet  15 , a cam (not shown) and the like. 
         [0026]    The pump body upper part  11  is formed substantially cylindrical and is secured to an upper part of a pump body lower part (not shown). In an axial part of a lower end surface of the pump body upper part  11 , a plunger spring chamber  11   a  is formed in which the plunger spring  14  and the tappet  15  are provided and whose lower side is opened. In an axial part of an upper end surface of the pump body upper part  11 , a barrel holding hole  11   b  is formed which holds the barrel  12  and whose upper side is opened. The barrel holding hole  11   b  is communicated with the plunger spring chamber  11   a  in the pump body upper part  11 . In a vertical middle part of the barrel holding hole  11   b  of the pump body upper part  11 , a circular diameter-expanded part is formed. The circular diameter-expanded part constitutes an outer side surface of a fuel supply/exhaust chamber  11   c . In an outer peripheral surface of the pump body upper part  11 , a fuel supply port  11   d  is formed so as to be communicated with the fuel supply/exhaust chamber  11   c . The fuel supply port  11   d  is connected to the low pressure pump (not shown). 
         [0027]    In the barrel  12 , the plunger  13  is provided so as to be slidable along an axial direction, that is, along the vertical direction. The barrel  12  is formed substantially cylindrical and inserted into the barrel holding hole  11   b  of the pump body upper part  11  snugly so that upper and lower ends of the barrel  12  are projected vertically from the barrel holding hole  11   b . In an axial part of the barrel  12 , a plunger hole  12   a  is formed in which the plunger  13  is provided and whose lower end is opened. In the axial part of the barrel  12 , at a side upper than the plunger hole  12   a , a first fuel supply path  12   b  is formed so as to be extended vertically. The first fuel supply path  12   b  is communicated with the plunger hole  12   a . At the upper end of the barrel  12 , a flange is formed so as to be projected radially. 
         [0028]    The barrel  12  is secured via the flange to an upper end of the pump body upper part  11  by bolts or the like while being inserted in the barrel holding hole  11   b . Accordingly, the circular diameter-expanded part of the barrel holding hole  11   b  and an outer peripheral surface of the barrel  12  constitute the fuel supply/exhaust chamber  11   c . In a side of the barrel  12  outer than the first fuel supply path  12   b  in a radial direction, a first spill oil exhaust path  12   c  is formed substantially vertically. The first spill oil exhaust path  12   c  is communicated with the fuel supply/exhaust chamber  11   c  of the pump body upper part  11 . 
         [0029]    The plunger  13  pressurizes the fuel. The plunger  13  is formed substantially cylindrical and inserted into the plunger hole  12   a  snugly so as to be slidable vertically. A pressurizing chamber  16  is formed by an upper end surface of the plunger  13  and the plunger hole  12   a . The pressurizing chamber  16  is communicated with the fuel supply/exhaust chamber  11   c  via a suction path  12   d  formed in the barrel  12 . 
         [0030]    The plunger spring  14  is a compression spring and biases the plunger  13  downward. The plunger spring  14  is arranged in a lower part of the plunger  13  while an expansion/contraction direction of the plunger spring  14  is in agreement with the vertical direction. A lower end of the plunger spring  14  is supported by the plunger  13  via a plunger spring receiver  14   a , and an upper end of the plunger spring  14  contacts the pump body upper part  11  via a plunger spring receiver  14   b . Namely, the plunger spring  14  biases the plunger  13  downward from the pump body upper part  11 . 
         [0031]    The tappet  15  transmits pressing force from the cam (not shown) to the plunger  13 . The tappet  15  is formed like a bottomed cylinder and inserted into the plunger spring chamber  11   a  snugly so as to be slidable vertically. Inside the tappet  15 , the lower part of the plunger  13 , a lower part of the plunger spring  14 , and the plunger spring receiver  14   a  are arranged. A roller (not shown) is supported rotatably at a bottom of the tappet  15  so as to face the cam arranged below. The tappet  15  contacts the cam via the roller by biasing force of the plunger spring  14 . The tappet  15  receives the pressing force from the cam via the roller and transmits it to the plunger  13 . Accordingly, the plunger  13  is moved vertically following rotation of the cam. 
         [0032]    The electromagnetic spill valve  20  adjusts fuel injection amount and injection timing of the fuel injection pump  1 . The electromagnetic spill valve  20  has a housing  21 , an insert piece  22 , a spill valve body  23 , a stopper  24 , a solenoid  25  and the like. 
         [0033]    The housing  21  is a structure constituting a body part of the electromagnetic spill valve  20 . The housing  21  is formed in a substantially rectangular parallelepiped shape. In an upper part of the housing  21 , a two-way delivery valve spring chamber  21   a  is formed vertically. The two-way delivery valve spring chamber  21   a  is expanded radially upward from a middle part of the two-way delivery valve spring chamber  21   a  so as to form a discharge valve chamber  21   f . In a lower part of the housing  21 , a second fuel supply path  21   b  is formed vertically. The second fuel supply path  21   b  is formed so as to be communicated with the two-way delivery valve spring chamber  21   a  via a lower surface of the housing  21 . A diameter of the two-way delivery valve spring chamber  21   a  is larger than that of the second fuel supply path  21   b.    
         [0034]    As shown in  FIG. 2 , in a vertical middle part of the housing  21 , an insert piece hole  21   d  is formed so as to penetrate the housing  21  laterally. The insert piece hole  21   d  crosses and is communicated with the second fuel supply path  21   b . Accordingly, the insert piece hole  21   d  is communicated with the two-way delivery valve spring chamber  21   a  via the second fuel supply path  21   b . A part of the insert piece hole  21   d  on the right of a middle part thereof, which is on the left of the second fuel supply path  21   b , is contracted radially so as to form a stepped part  21   g . A female thread part is formed in a left end of the insert piece hole  21   d.    
         [0035]    In a part on the left of the second fuel supply path  21   b  of the housing  21 , a second spill oil exhaust path  21   c  is formed vertically. The second spill oil exhaust path  21   c  is communicated with the insert piece hole  21   d . The housing  21  is secured to the barrel  12  by bolts or the like while a lower end surface of the housing  21  touches closely an upper end surface of the barrel  12 . The second fuel supply path  21   b  is communicated with the first fuel supply path  12   b  of the barrel  12 , and the second spill oil exhaust path  21   c  is communicated with the first spill oil exhaust path  12   c  of the barrel  12 . 
         [0036]    In the housing  21 , a securing hole  21   h  is formed which constitutes a securing means securing the insert piece  22 . The securing hole  21   h  is communicated with the insert piece hole  21   d  via a part of an upper surface of the housing  21  on the left of the second fuel supply path  21   b . A female thread part is formed in a lower part of the securing hole  21   h . A securing screw  26  which is a securing member constituting the securing means is inserted into the securing hole  21   h  and arranged in the female thread part. The position at which the securing hole  21   h  is not limited to that of this embodiment and may be another position which is communicated with the insert piece hole  21   d.    
         [0037]    The insert piece  22  is a member on which the spill valve body  23  is seated. The insert piece  22  is formed substantially like a cylinder whose total length is shorter than the insert piece hole  21   d . A part of the insert piece  22  from a middle part thereof is contracted radially so as to form a stepped part  22   f . The insert piece  22  is inserted into the insert piece hole  21   d  snugly and detachably so that the stepped part  22   f  contacts the stepped part  21   g  of the insert piece hole  21   d . A left end of the insert piece  22  is biased by the stopper  24  and is provided inside the insert piece hole  21   d . A fuel supply hole  22   a  is formed in a part of the insert piece  22 , which faces the second fuel supply path  21   b  when the insert piece  22  is provided inside the insert piece hole  21   d , so as to penetrate an inner perimeter of the insert piece  22 . 
         [0038]    In an outer peripheral part of a diameter-expanded side (left side) of the stepped part  22   f  of the insert piece  22 , a notched part  22   h  constituting the securing means is formed at a position facing the securing hole  21   h  of the housing  21 . The notched part  22   h  is formed at a depth not communicated with the inner perimeter of the insert piece  22  with a width substantially the same as a diameter of the securing screw  26 . The securing screw  26  secured to the female thread part of the securing hole  21   h  is inserted into the notched part  22   h . Namely, the insert piece  22  is secured to an inside of the insert piece hole  21   d  by the securing means (the securing hole  21   h , the securing screw  26  and the notched part  22   h ). Accordingly, it is not necessary to press-inserting the insert piece  22  into the insert piece hole  21   d  for securing. 
         [0039]    The inner perimeter of the insert piece  22  is diameter-expanded at the left of the fuel supply hole  22   a  so as to form a first diameter-expanded part  22   d . In an inner peripheral surface of the insert piece  22 , a valve seat  22   b  is provided at a right end of the first diameter-expanded part  22   d  which is tapered so as to be diameter-expanded leftward continuously. Furthermore, the inner perimeter of the insert piece  22  is diameter-contracted at the left of the first diameter-expanded part  22   d  so as to form a second diameter-expanded part  22   e . The inner diameter of the first diameter-expanded part  22   d  is larger than that of the second diameter-expanded part  22   e . In a part of the first diameter-expanded part  22   d  of the insert piece  22  facing the second spill oil exhaust path  21   c  of the housing  21 , a spill oil exhaust port  22   c  is formed so as to penetrate the inner perimeter of the insert piece  22 . 
         [0040]    The spill valve body  23  switches a passage of fuel pressingly sent in the second fuel supply path  21   b . The spill valve body  23  is slidably inserted into the insert piece  22 . A diameter-contracted part  23   a  whose diameter is smaller than that of the spill valve body  23  is provided in a part of the spill valve body  23  crossing the fuel supply hole  22   a  of the insert piece  22  when the spill valve body  23  is inserted into the insert piece  22 . Accordingly, a space is formed between the spill valve body  23  and the insert piece  22 , whereby a flow of fuel in the second fuel supply path  21   b  over the insert piece  22  is not blocked. In the spill valve body  23 , at a left end of the diameter-contracted part  23   a , a seal surface  23   b  is provided which is tapered so as to be diameter-expanded leftward. The seal surface  23   b  can be seated snugly on the valve seat  22   b  of the insert piece  22 . 
         [0041]    A part of the spill valve body  23  between a left end surface thereof and the seal surface  23   b  is diameter-expanded so as to form a diameter-expanded part  23   c  whose diameter is substantially the same as the inner diameter of the second diameter-expanded part  22   e  of the insert piece  22 . A part of the spill valve body  23  at the right of the diameter-contracted part  23   a  is inserted slidably into the insert piece  22 , and the diameter-expanded part  23   c  is inserted slidably into the second diameter-expanded part  22   e  of the insert piece  22 . Namely, more than half of a length in an axial direction of the spill valve body  23  is inserted into only the insert piece  22  provided inside the housing  21 , and the spill valve body  23  is guided by only the insert piece  22  when the spill valve body  23  is slid. The spill valve body  23  is biased leftward by a spill valve spring  23   e  provided inside a right end of the insert piece hole  21   d . In a right end of the spill valve body  23 , an armature  23   d  including a magnetic body is disposed. 
         [0042]    The stopper  24  restricts sliding of the spill valve body  23 . The stopper  24  has a contact surface  24   a  at a right end surface thereof and is formed substantially cylindrical so as to be able to be secured to the insert piece hole  21   d  of the housing  21 . The stopper  24  is inserted rightward into the insert piece hole  21   d  of the housing  21  so that the contact surface  24   a  contacts a left end surface of the insert piece  22  provided inside the insert piece hole  21   d . Accordingly, the stopper  24  secures the insert piece  22  so that the insert piece  22  cannot be moved in the insert piece hole  21   d  along an axial direction. The stopper  24  is configured so that a left end of the spill valve body  23  touches the contact surface  24   a  when the spill valve body  23  is slid leftward. Accordingly, the stopper  24  can restrict a sliding amount of the spill valve body  23 . 
         [0043]    The solenoid  25  generates magnetic force. The solenoid  25  is secured to the housing  21  so that an adsorption surface faces the armature  23   d  disposed in the spill valve body  23 . By receiving a signal from a control device (not shown), the solenoid  25  generates the magnetic force so as to adsorb the armature  23   d  disposed in the spill valve body  23 . Accordingly, the solenoid  25  slides the spill valve body  23  rightward based on the signal from the control device (not shown). 
         [0044]    According to the above, in the electromagnetic spill valve  20 , when the spill valve body  23  is slid leftward by the spill valve spring  23   e , the seal surface  23   b  of the spill valve body  23  is separated from the valve seat  22   b  of the insert piece  22 . As a result, the second fuel supply path  21   b  is communicated with the second spill oil exhaust path  21   c  via the fuel supply hole  22   a , an inside of the first diameter-expanded part  22   d  and the spill oil exhaust port  22   c  of the insert piece  22 . 
         [0045]    On the other hand, when the spill valve body  23  is slid rightward by the solenoid  25  oppositely to biasing force of the spill valve spring  23   e , the seal surface  23   b  of the spill valve body  23  is seated on the valve seat  22   b  of the insert piece  22 . As a result, the communication of the second fuel supply path  21   b  and the second spill oil exhaust path  21   c  is cut off. 
         [0046]    As shown in  FIG. 1 , the two-way delivery valve part  30  discharges fuel and maintains pressure of fuel in a high pressure pipe joint  35  after finishing the injection to a predetermined value. The two-way delivery valve part  30  has a two-way delivery valve body  32 , a discharge valve  33 , a two-way delivery valve  34  and the like. The two-way delivery valve part  30  is connected to the high pressure pipe joint  35 . 
         [0047]    The two-way delivery valve body  32  is formed like a cylinder whose lower end surface has substantially the same shape as an upper end surface of the housing  21 . The two-way delivery valve body  32  is secured to the housing  21  by bolts or the like while the lower end surface of the two-way delivery valve body  32  contacts snugly the upper end surface of the housing  21 . In a lower part of the two-way delivery valve body  32 , a discharge valve spring chamber  32   a  is formed vertically and arranged oppositely to the discharge valve chamber  21   f . The discharge valve spring chamber  32   a  is communicated with the two-way delivery valve spring chamber  21   a  and the discharge valve chamber  21   f . In an inner peripheral surface of an upper part of the two-way delivery valve body  32 , a circular seal surface  32   c  is formed which is shaped like a funnel diameter-contracted downward continuously so as to fasten the high pressure pipe joint  35  tightly. In a vertical middle part of the two-way delivery valve body  32 , a discharge port  32   b  is opened. The discharge valve spring chamber  32   a  is communicated with the outside via the discharge port  32   b.    
         [0048]    As shown in  FIGS. 1 and 2 , the discharge valve  33  discharges fuel via the discharge port  32   b . The discharge valve  33  includes a discharge valve body  33   a  and a discharge valve spring  33   c . The discharge valve body  33   a  is formed substantially cylindrical and provided inside the discharge valve chamber  21   f  so that a space through which fuel with high pressure can pass is formed between the discharge valve body  31  and an inner peripheral surface of the discharge valve chamber  21   f . The discharge valve spring  33   c  is provided inside the discharge valve chamber  21   f  above the discharge valve body  33   a . The discharge valve body  33   a  is biased downward by the discharge valve spring  33   c  so that a lower end surface of the discharge valve body  33   a  is seated on a lower end surface of the discharge valve chamber  21   f . In a lower part of the discharge valve body  33   a , a recess opened downward is formed. An inside of the recess is a two-way delivery valve chamber  33   d . In an upper part of the discharge valve body  33   a , a two-way delivery valve path  33   b  is formed vertically. A lower side of the two-way delivery valve path  33   b  is communicated with the two-way delivery valve chamber  33   d , and an upper side thereof is communicated with the discharge valve spring chamber  32   a.    
         [0049]    The two-way delivery valve  34  opens and closes the two-way delivery valve path  33   b . The two-way delivery valve  34  includes a two-way delivery valve body  34   a  and a two-way delivery valve spring  34   b . The two-way delivery valve body  34   a  includes a ball and a receiver. The receiver is provided inside the two-way delivery valve chamber  33   d  so that a space through which fuel can pass is formed between the receiver and an inner peripheral surface of the two-way delivery valve chamber  33   d . The ball is arranged on the receiver so as to be seated on an opening of the two-way delivery valve path  33   b  opened in an upper surface of the two-way delivery valve chamber  33   d . The two-way delivery valve body  34   a  contacts the two-way delivery valve spring  34   b , provided inside the two-way delivery valve spring chamber  21   a , with a lower end surface of the receiver, and is biased upward by the two-way delivery valve spring  34   b . Accordingly, in the two-way delivery valve  34 , by biasing force of the two-way delivery valve spring  34   b , the two-way delivery valve body  34   a  cuts off the communication of the two-way delivery valve chamber  33   d  and the two-way delivery valve path  33   b.    
         [0050]    The high pressure pipe joint  35  supplies fuel with high pressure to the fuel injection nozzle (not shown). In an outer peripheral surface of one of sides (a side of the discharge port  32   b ) of the high pressure pipe joint  35 , a circular seal surface  35   a  is formed which is tapered so as to be diameter-contracted downward continuously. The high pressure pipe joint  35  is attached to the two-way delivery valve body  32  while being pressed so that the seal surface  35   a  contacts snugly the seal surface  32   c  of the two-way delivery valve body  32 . Inside the high pressure pipe joint  35 , a fuel supply path  35   b  is formed. The fuel supply path  35   b  is communicated with the discharge port  32   b.    
         [0051]    The fuel injection pump  1  according to the present invention is a PF type fuel injection pump in which a tappet is provided in an engine. However, the fuel injection pump is not limited thereto and may alternatively be a PFR type fuel injection pump in which a tappet is provided in a fuel injection pump body part, for example. 
         [0052]    Next, an explanation will be given on an operation mode of the electromagnetic spill valve  20  in the fuel injection pump  1  referring to  FIG. 3 . 
         [0053]    Fuel is supplied to the fuel supply/exhaust chamber  11   c  via the fuel supply port  11   d  of the pump body upper part  11  by the low pressure pump (not shown). The fuel supplied into the fuel supply/exhaust chamber  11   c  is supplied to the pressurizing chamber  16  via the first spill oil exhaust path  12   c  of the barrel  12  when the plunger  13  falls down. The fuel in the pressurizing chamber  16  is pressurized by the plunger  13  slid upward following rotation of the cam (not shown), and supplied to the pressurizing chamber  16 , the first fuel supply path  12   b  and the second fuel supply path  21   b  of the housing  21  in this order. 
         [0054]    When the fuel injection pump  1  discharges fuel, as shown in  FIG. 3(   a ), the solenoid  25  of the electromagnetic spill valve  20  is excited based on a signal from the control device (not shown). The spill valve body  23  of the electromagnetic spill valve  20  is slid rightward (along a direction of a void arrow) by attracting force of the solenoid  25 . Then, the seal surface  23   b  of the spill valve body  23  is seated on the valve seat  22   b  of the insert piece  22 . As a result, the communication of the second fuel supply path  21   b  and the second spill oil exhaust path  21   c  of the housing  21  is cut off, whereby fuel pressure in the second fuel supply path  21   b  is not released via the second spill oil exhaust path  21   c  and is maintained. Accordingly, pressurized fuel flows along a direction of a black arrow and the two-way delivery valve spring chamber  21   a  is filled up with the fuel from the pressurizing chamber  16  (see  FIG. 1)  via the first fuel supply path  12   b  and the second fuel supply path  21   b . Namely, the electromagnetic spill valve  20  is closed and fuel is enabled to be supplied. 
         [0055]    When power applied to the discharge valve body  33   a  of the discharge valve  33  (the two-way delivery valve body  34   a  of the two-way delivery valve  34 ) by fuel pressure in the two-way delivery valve spring chamber  21   a  becomes larger than biasing force of the discharge valve spring  33   c  biasing downward the discharge valve body  33   a , the discharge valve body  33   a  is moved upward and separated from the lower end surface of the discharge valve chamber  21   f , whereby the discharge valve  33  is opened. At this time, the two-way delivery valve  34  is closed. As a result, pressurized fuel flows from the two-way delivery valve spring chamber  21   a  to the discharge valve spring chamber  32   a  and discharged from the discharge valve spring chamber  32   a  via the discharge port  32   b  to the fuel supply path  35   b  of the high pressure pipe joint  35  (see  FIG. 1 ). 
         [0056]    When the fuel pressure in the two-way delivery valve spring chamber  21   a  is released as the above, by the biasing force of the discharge valve spring  33   c  biasing downward the discharge valve body  33   a , the discharge valve body  33   a  is moved downward and seated on the lower end surface of the discharge valve chamber  21   f , whereby the discharge valve  33  is closed. As a result, the fuel is not discharged from the discharge valve spring chamber  32   a  via the discharge port  32   b  to the fuel supply path  35   b . At this time, pulsation is generated in the fuel pressure remaining between the fuel supply path  35   b , positioned downstream the discharge valve  33 , and the fuel injection nozzle (not shown). When power applied to the two-way delivery valve body  34   a  by the generated pulsation of the fuel pressure is larger than the biasing force of the two-way delivery valve spring  34   b  biasing the two-way delivery valve body  34   a  upward (toward the discharge port  32   b ), the two-way delivery valve body  34   a  is moved downward (oppositely to the discharge port  32   b ), whereby the two-way delivery valve  34  is opened. Accordingly, the fuel pressure increased by the pulsation is released and reduced to a predetermined value. 
         [0057]    When the fuel injection pump  1  stops discharge of fuel, as shown in  FIG. 3(   b ), the solenoid  25  of the electromagnetic spill valve  20  is demagnetized based on a signal from the control device (not shown). By biasing force of the spill valve spring  23   e , the spill valve body  23  of the electromagnetic spill valve  20  is slid leftward (along a direction of a void arrow) until the spill valve body  23  contacts the contact surface  24   a  of the stopper  24 . Then, the seal surface  23   b  of the spill valve body  23  is separated from the valve seat  22   b  of the insert piece  22 . As a result, the second fuel supply path  21   b  and the second spill oil exhaust path  21   c  of the housing  21  are communicated with each other, whereby fuel pressure in the second fuel supply path  21   b  is released via the second spill oil exhaust path  21   c . Accordingly, fuel flows from the second fuel supply path  21   b  to the fuel supply hole  22   a , the inside of the first diameter-expanded part  22   d  and the spill oil exhaust port  22   c  of the insert piece  22 , and the second spill oil exhaust path  21   c  in this order along a black arrow, and then discharged via the first spill oil exhaust path  12   c  to the fuel supply/exhaust chamber  11   c , and is not discharged to the fuel supply path  35   b  of the high pressure pipe joint  35 . Namely, the electromagnetic spill valve  20  is opened and fuel cannot be supplied. 
         [0058]    At this time, the insert piece  22  is secured to the inside of the insert piece hole  21   d  of the housing  21  by the securing means (the securing hole  21   h , the securing screw  26  and the notched part  22   h ) so as not to be rotatable around an axis in the insert piece hole  21   d . Accordingly, the second fuel supply path  21   b  is not blocked by the insert piece  22 . 
         [0059]    As the above, the fuel injection pump  1 , which is the first embodiment of the fuel injection pump according to the present invention, has the electromagnetic spill valve  20 . The electromagnetic spill valve  20  has the housing  21  in which the insert piece hole  21   d  is formed, the insert piece  22  formed substantially like a cylinder whose inner peripheral surface is provided therein with the valve seat  22   b  and inserted detachably into the insert piece hole  21   d , the spill valve body  23  formed substantially like a cylinder whose outer peripheral surface is provided therein with the seal surface  23   b  which can be seated on the valve seat  22   b  and inserted slidably into the insert piece  22 , and the securing means securing the position of the insert piece  22  around the axis concerning the insert piece hole  21   d.    
         [0060]    According to the configuration, the insert piece  22  can be attached to the housing  21  while being rotatable in the insert piece hole  21   d . Accordingly, a position of the second fuel supply path  21   b  of the housing  21  can be matched easily to a position of the fuel supply hole  22   a  which is a fuel path of the insert piece  22 , and the insert piece  22  can be secured in the housing  21  by the securing means so as not to be rotatable. 
         [0061]    The securing means includes the securing hole  21   h  communicated with the insert piece hole  21   d  from a side surface of the housing  21 , the notched part  22   h  formed in the outer peripheral surface of the insert piece  22  facing the securing hole  21   h , and the securing screw  26  which is the securing member inserted into the securing hole  21   h  and the notched part  22   h.    
         [0062]    According to the configuration, the insert piece  22  is secured to a predetermined position of the housing  21  by the securing screw  26  which is the securing member. Accordingly, a position of the second fuel supply path  21   b  of the housing  21  can be matched easily to a position of the fuel supply hole  22   a  which is a fuel path of the insert piece  22 , and the insert piece  22  can be secured in the housing  21  by the securing means so as not to be rotatable. 
         [0063]    An explanation will be given on an electromagnetic spill valve  40  of the fuel injection pump  1  which is a second embodiment of the fuel injection pump according to the present invention referring to  FIG. 4 . In below embodiment, concrete explanations of points the same as the first embodiment explained above are omitted, and points different from the first embodiment are mainly explained. 
         [0064]    The electromagnetic spill valve  40  opens and closes the first spill oil exhaust path  12   c  and a second spill oil exhaust path  41   c  for releasing fuel compressed in the pressurizing chamber  16  to the fuel supply/exhaust chamber  11   c  of a low pressure side so as to control fuel injection of the fuel injection pump  1 . The electromagnetic spill valve  40  has a housing  41 , an insert piece  42 , a spill valve body  43 , the stopper  24 , the solenoid  25  and the like. 
         [0065]    The housing  41  is a structure constituting a body part of the electromagnetic spill valve  40 . The housing  41  is formed in a substantially rectangular parallelepiped shape. In a vertical middle part of the housing  41 , an insert piece hole  41   d  is formed so as to penetrate the housing  41  laterally. A part of the insert piece hole  41   d  on the left of a middle part thereof, which is on the left of a second fuel supply path  41   b , is contracted radially so as to form a middle stepped part  41   g . A left stepped part  41   j  is formed by contracting radially the insert piece hole  41   d  rightward from a left end thereof. A female thread part is formed in the diameter-expanded part. 
         [0066]    Furthermore, in the housing  41 , as shown in  FIG. 4(   b ), a housing side notched part  41   h  is formed which constitutes a securing means securing the insert piece  42 . The housing side notched part  41   h  is formed rightward from the left stepped part  41   j  of the insert piece hole  41   d  at a depth not communicated with the second fuel supply path  41   b  so that a section in an axial direction of the insert piece hole  41   d  is formed substantially like a semicircle. 
         [0067]    The insert piece  42  is a member on which the spill valve body  43  is seated. A part of the insert piece  42  from a middle part thereof is contracted radially so as to form a stepped part  42   f . The insert piece  42  is inserted into the insert piece hole  41   d  snugly and detachably so that the stepped part  42   f  contacts the middle stepped part  41   g  of the insert piece hole  41   d.    
         [0068]    In an outer perimeter of a diameter-expanded side (left side) of the stepped part  42   f  of the insert piece  42 , at a position facing the housing side notched part  41   h  of the housing  41 , an insert piece side notched part  42   h  is formed which constitutes the securing means. The insert piece side notched part  42   h  is formed at a depth not communicated with the inner perimeter thereof so that a section in an axial direction of the insert piece  42  is formed substantially like a semicircle. Namely, the insert piece side notched part  42   h  is formed so that the housing side notched part  41   h  and the insert piece side notched part  42   h  constitute a pin hole part whose section in an axial direction is formed circularly. The securing means is not limited to that having a securing pin  46  whose section is circular shaped, and any securing means is available if the insert piece  42  is secured to an inside of the insert piece hole  41   d  (for example, a securing key whose section is rectangular shaped). 
         [0069]    The securing pin  46  which is a securing member constituting the securing means is inserted into the housing side notched part  41   h  and the insert piece side notched part  42   h . Namely, the insert piece  42  is secured to the inside of the insert piece hole  41   d  by the securing means (the housing side notched part  41   h , the insert piece side notched part  42   h  and the securing pin  46 ). Then, the stopper  24  is attached to the diameter-expanded part of the housing  41  in which the left stepped part  41   j  is formed. 
         [0070]    Accordingly, the insert piece  42  can be secured without being press-inserted into the insert piece hole  41   d . Since the insert piece  42  is secured to the inside of the insert piece hole  41   d  of the housing  41  by the securing means (the housing side notched part  41   h , the insert piece side notched part  42   h  and the securing pin  46 ), the insert piece  42  is not rotated around an axis in the insert piece hole  41   d . Furthermore, by the stopper  24 , the insert piece  42  and the securing pin  46  are secured to the inside of the housing  41  while being sealed. 
         [0071]    As the above, the securing means of the electromagnetic spill valve  40  of the fuel injection pump  1 , which is the second embodiment of the fuel injection pump according to the present invention, includes the housing side notched part  41   h  formed in an inner peripheral surface of the insert piece hole  41   d , the insert piece side notched part  42   h  formed in an outer peripheral surface of the insert piece  42  facing the housing side notched part  41   h , the securing pin  46  which is the securing member inserted into the housing side notched part  41   h  and the insert piece side notched part  42   h , and the stopper  24  which is a sealing member sealing the insert piece  42  and the securing pin  46  to the inside of the housing  41 . 
         [0072]    According to the configuration, the insert piece  42  is secured by the securing pin  46  which is the securing means configured between the insert piece hole  41   d  and the insert piece  42 . Accordingly, the securing pin  46  is sealed in an inside of the housing  41  by the stopper  24  and is not exposed outside, whereby oil leak from the securing pin  46  can be prevented. A position of the second fuel supply path  41   b  of the housing  41  can be matched easily to a position of a fuel supply hole  42   a  which is a fuel path of the insert piece  42 , and the insert piece  42  can be secured in the housing  41  by the securing means so as not to be rotatable. 
         [0073]    An explanation will be given on an electromagnetic spill valve  50  of the fuel injection pump  1  which is a third embodiment of the fuel injection pump according to the present invention referring to  FIG. 5 . In below embodiment, concrete explanations of points the same as the first embodiment explained above are omitted, and points different from the first embodiment are mainly explained. 
         [0074]    The electromagnetic spill valve  50  opens and closes the first spill oil exhaust path  12   c  and a second spill oil exhaust path  51   c  for releasing fuel compressed in the pressurizing chamber  16  to the fuel supply/exhaust chamber  11   c  of a low pressure side so as to control fuel injection of the fuel injection pump  1 . The electromagnetic spill valve  50  has a housing  51 , an insert piece  52 , a spill valve body  53 , the stopper  24 , the solenoid  25  and the like. 
         [0075]    The housing  51  is a structure constituting a body part of the electromagnetic spill valve  50 . The housing  51  is formed in a substantially rectangular parallelepiped shape. In a vertical middle part of the housing  51 , an insert piece hole  51   d  is formed so as to penetrate the housing  51  laterally. In the insert piece hole  51   d , on the left of a second fuel supply path  51   b , housing side flat surface parts  51   h  are formed which constitute a securing means securing the insert piece  52 . The housing side flat surface parts  51   h  are formed by shaping parts of an inner side surface of the insert piece hole  51   d  facing each other to be flat surfaces. At this time, a distance between the housing side flat surface parts  51   h  facing each other is smaller than a diameter of the insert piece hole  51   d  (see  FIG. 5(   c )). 
         [0076]    The insert piece  52  is a member on which the spill valve body  53  is seated. A part of the insert piece  52  from a middle part thereof is contracted radially so as to form a stepped part  52   f . The insert piece  52  is inserted into the insert piece hole  51   d  snugly and detachably so that the stepped part  52   f  contacts the stepped part  51   g  of the insert piece hole  51   d . In an outer perimeter of a diameter-expanded side (left side) of the stepped part  52   f  of the insert piece  52 , at positions facing the housing side flat surface parts  51   h  of the housing  51 , insert piece side flat surface parts  52   h  are formed respectively which constitute the securing means. 
         [0077]    The insert piece  52  is inserted into the insert piece hole  51   d  so that the insert piece side flat surface parts  52   h  contact the housing side flat surface parts  51   h  snugly. Namely, the insert piece  52  is secured to the inside of the insert piece hole  51   d  by the securing means (the housing side flat surface parts  51   h  and the insert piece side flat surface parts  52   h ). Accordingly, the insert piece  52  can be secured without being press-inserted into the insert piece hole  51   d . In this embodiment, the two insert piece side flat surface parts  52   h  are provided at positions whose phases are different for 180°. However, the number of the insert piece side flat surface parts  52   h  may alternatively be one, or three or more. 
         [0078]    Since the insert piece  52  is secured to the inside of the insert piece hole  51   d  of the housing  51  by the securing means (the housing side flat surface parts  51   h  and the insert piece side flat surface parts  52   h ), the insert piece  52  is not rotated around an axis in the insert piece hole  51   d.    
         [0079]    As the above, the securing means of the electromagnetic spill valve  50  of the fuel injection pump  1 , which is the second embodiment of the fuel injection pump according to the present invention, includes the housing side flat surface parts  51   h  formed in the inner peripheral surface of the insert piece hole  51   d , and the insert piece side flat surface parts  52   h  formed in the outer peripheral surface of the insert piece  52  facing the housing side flat surface parts  51   h.    
         [0080]    According to the configuration, the insert piece  52  is secured to a predetermined position of the housing  51  without any securing member. Accordingly, it is not necessary to provide the securing member, whereby number of assembly processes can be reduced. A position of the second fuel supply path  51   b  of the housing  51  can be matched easily to a position of a fuel supply hole  52   a  which is a fuel path of the insert piece  52 , and the insert piece  52  can be secured in the housing  51  so as not to be rotatable. 
         [0081]    An explanation will be given on an electromagnetic spill valve  60  of the fuel injection pump  1  which is another embodiment of the fuel injection pump according to the present invention referring to  FIG. 6 . In the electromagnetic spill valve  60  of this embodiment, it is not necessary to secure rotation of an insert piece around an axis and to adjust a position of the insert piece. In below embodiment, concrete explanations of points the same as the first embodiment explained above are omitted, and points different from the first embodiment are mainly explained. 
         [0082]    The electromagnetic spill valve  60  opens and closes the first spill oil exhaust path  12   c  and a second spill oil exhaust path  61   c  for releasing fuel compressed in the pressurizing chamber  16  to the fuel supply/exhaust chamber  11   c  of a low pressure side so as to control fuel injection of the fuel injection pump  1 . The electromagnetic spill valve  60  has a housing  61 , an insert piece  62 , a spill valve body  63 , the stopper  24 , the solenoid  25  and the like. 
         [0083]    The housing  61  is a structure constituting a body part of the electromagnetic spill valve  60 . The housing  61  is formed in a substantially rectangular parallelepiped shape. In a vertical middle part of the housing  61 , an insert piece hole  61   d  is formed so as to penetrate the housing  61  laterally. 
         [0084]    The insert piece  62  is a member on which the spill valve body  63  is seated. A part of the insert piece  62  from a middle part thereof is contracted radially so as to form a stepped part  62   f . The insert piece  62  is inserted into the insert piece hole  61   d  snugly and detachably so that the stepped part  62   f  contacts the stepped part  61   g  of the insert piece hole  61   d.    
         [0085]    In an outer peripheral surface of the insert piece  62  facing a second fuel supply path  61   b  in the insert piece hole  61   d , a fuel supply groove  62   h  is formed along the whole circumference. In the fuel supply groove  62   h , a fuel supply hole  62   a  is formed at a position which faces the second fuel supply path  61   b  so as to penetrate an inner perimeter of the insert piece  62 . Namely, the second fuel supply path  61   b  is communicated via the fuel supply hole  62   a  with a two-way delivery valve spring chamber  61   a  and communicated via the fuel supply groove  62   h  with the two-way delivery valve spring chamber  61   a.    
         [0086]    Similarly, in the outer peripheral surface of the insert piece  62  facing the second spill oil exhaust path  61   c , a spill oil exhaust groove  62   j  is formed along the whole circumference. In the spill oil exhaust groove  62   j , a spill oil exhaust port  62   c  is formed at a position which faces the second spill oil exhaust path  61   c  so as to penetrate the inner perimeter of the insert piece  62 . Namely, the second spill oil exhaust path  61   c  is communicated via the spill oil exhaust port  62   c  with an inside of the insert piece  62  and communicated via the spill oil exhaust groove  62   j  and the spill oil exhaust port  62   c  with the inside of the insert piece  62 . 
         [0087]    When the fuel injection pump  1  discharges fuel, by the electromagnetic spill valve  60  operated based on a signal from the control device (not shown), the communication of the second fuel supply path  61   b  and the second spill oil exhaust path  61   c  of the housing  61  is cut off. Accordingly, fuel pressure in the second fuel supply path  61   b  is not released via the second spill oil exhaust path  61   c  and is maintained. Then, an inside of the two-way delivery valve spring chamber  61   a  is filled up with pressurized fuel flowing via an inside of the pressurizing chamber  16  (see  FIG. 1 ), an inside of the first fuel supply path  12   b , an inside of the second fuel supply path  61   b , and the fuel supply hole  62   a  of the insert piece  62 . 
         [0088]    At this time, even if the insert piece  62  is rotated in the insert piece hole  61   d  so that the second fuel supply path  61   b  does not face the fuel supply hole  62   a , the pressurized fuel reaches the inside of the two-way delivery valve spring chamber  61   a  via the fuel supply groove  62   h  of the insert piece  62 . Namely, even if the insert piece  62  is rotated in the insert piece hole  61   d , fuel supply is not prevented. 
         [0089]    When the fuel injection pump  1  stops discharge of fuel, based on a signal from the control device (not shown), the second fuel supply path  61   b  is communicated with the second spill oil exhaust path  61   c  by the electromagnetic spill valve  20 . Accordingly, fuel pressure in the second fuel supply path  61   b  is released via the second spill oil exhaust path  61   c . Then, fuel is discharged from the second fuel supply path  61   b  via the fuel supply hole  62   a  of the insert piece  62 , the inside of the insert piece  62 , the spill oil exhaust port  62   c  of the insert piece  62  and the second spill oil exhaust path  61   c  to the fuel supply/exhaust chamber  11   c.    
         [0090]    At this time, even if the insert piece  62  is rotated in the insert piece hole  61   d  so that the second fuel supply path  61   b  does not face the fuel supply hole  62   a  and the second spill oil exhaust path  61   c  does not face the spill oil exhaust port  62   c , fuel in the second fuel supply path  61   b  reaches the inside of the insert piece  62  via the fuel supply groove  62   h  and the fuel supply hole  62   a . Then, the fuel reaching the inside of the insert piece  62  is discharged via the spill oil exhaust groove  62   j  and the spill oil exhaust port  62   c  into the fuel supply/exhaust chamber  11   c . Namely, even if the insert piece  62  is rotated in the insert piece hole  61   d , fuel supply is not prevented. 
         [0091]    According to the configuration, it is not necessary to make the position of the fuel path of the housing  61  in agreement with the position of the fuel path of the insert piece  62  and to secure the insert piece  62  so as not to be rotatable in the housing  61 . 
       INDUSTRIAL APPLICABILITY 
       [0092]    The present invention can be used for a fuel injection pump provided in a diesel engine. 
       DESCRIPTION OF NOTATIONS 
       [0000]    
       
         
           
               1  fuel injection pump 
               20  electromagnetic spill valve 
               21  housing 
               21   d  insert piece hole 
               22  insert piece 
               22   b  valve seat 
               23  spill valve body