JPH04109466U - Electronically controlled fuel injection device - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to provide an electronically controlled fuel injection device that can obtain the optimum fuel injection amount at startup. [Structure] In an electronically controlled fuel injection device equipped with an electromagnetic spill valve whose opening and closing are electronically controlled in the normal rotation range, part of the fuel pumped by the plunger 7 is released to reduce the amount of fuel pumped. A control spill port 20 is provided in the plunger 7, and a number of spill holes 21 equal to the number of cylinders are provided at equal positions on the same circumference on the cylinder side in which the plunger 7 reciprocates inside. As the jar 7 rotates, when the spill port 20 and the spill hole 21 come to a matching position, the spill hole 21 releases a part of the fuel through the spill port 20 and the fuel injection device inner chamber, and the fuel is injected. The configuration is such that the amount of pumping is controlled, and the electromagnetic spill valve is kept in the closed position at the time of starting, so that the spill port 20 and the spill hole 21 come to the matching position after the optimum amount of starting fuel is injected. , the relative position of the spill port 20 and the spill hole 21 is determined.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention enables the optimum fuel injection amount to be obtained over a wide range from startup to normal rotation range. This invention relates to a fuel injection device.

0002

[Conventional technology]

The first conventional example shown in Fig. 4 is a distributed fuel type installed in a diesel engine. Regarding the injection device, as shown in FIG. 4, the body 31 and the output of the diesel engine The drive shaft 32 rotates 1/2 in conjunction with the shaft, and the drive shaft 32 A feed port that is driven to suck up fuel from the fuel tank and supply it into the body 31. a pressure control valve 34 that controls the supply pressure of the feed pump 33, and a pressure control valve 34 that controls the supply pressure of the feed pump 33; A cam plate 35 that rotates in synchronization with the live shaft 32, and this cam plate. 35, and a face cam 36 provided on the fixed side. 6 and the cam lift caused by the rotation of the cam plate 35. and a plunger 38 that moves in the axial direction and pumps the fuel. ing.

0003 The fuel injection amount is determined by the diameter of the plunger 38 and the profile of the face cam 36. The fuel to be pumped is basically determined by the It is sent to the injection nozzle through a distribution passage 40. The plurality of distribution passages 40 are The plunger 38 is placed on the same circumference of the cylinder on which the plunger 38 slides back and forth. As the engine rotates, they are formed at equal intervals corresponding to the injection nozzles of each cylinder of the engine. ing.

0004 In addition, a plunger is used to change the fuel injection amount according to the engine rotation speed. Part of the fuel pressurized and pumped at -38 is released to control the amount of fuel pumped. A spill port 41 is formed in the plunger 38, and the plunger -38 is a spill ring that opens and closes the spill port 41 by relative movement in the axial direction. 42 is fitted externally, and the rotation of the drive shaft 32 is transmitted through this spill ring 42. It is configured to be moved in the axial direction by the governor 43 that is located in the The moving section of the ringer 38 is configured to be set according to the rotational speed.

[0005] Next, the operation will be explained. When the drive shaft 32 rotates, the feed pump 33 supplies fuel into the body 31. Also, the cam plate 35 rotates and the cam plate 35 rotates. Since the face cam 36 is engaged with the roller 37, it is fixed to the cam plate 35. The fixed plunger 38 rotates to the cam profile of the face cam 36. Based on this, it reciprocates in the axial direction. The operation of this plunger 38 causes the pressurized chamber to open. After the fuel is sucked into 44, it is pressurized and discharged from passage 45 through discharge port 39. It is pumped through the distribution path 40 to the injection nozzle.

[0006] Also, depending on the rotational speed of the drive shaft 32, the spill ring is caused by the governor 43. 42 is operated to move, and the rotational speed of the fuel pumping stroke by the plunger 38 is increased. By opening the spill port 41 into the body 31 when the , a part of the fuel supply amount is cut, and the fuel is supplied according to the rotation speed of the drive shaft 32. The injection amount is controlled.

[0007] The second conventional technology shown in FIGS. 5 and 6 is equipped on a diesel engine. Regarding the electronically controlled fuel injection device, the body 31 and the output shaft of the diesel engine The drive shaft 32 rotates synchronously and the fuel is driven by the drive shaft 32. A feed pump 33 that sucks up fuel from the tank and supplies it into the body 31, and a door. A cam plate 35 that rotates in synchronization with the live shaft 32, and this cam plate. 35, and a face cam 36 provided on the fixed side. 6 and the cam lift caused by the rotation of the cam plate 35. and a plunger 38 that moves in the axial direction and pumps the fuel. ing.

[0008] The fuel injection amount is determined by the diameter of the plunger 38 and the profile of the face cam 36. The fuel to be pumped is basically determined by the It is sent to the injection nozzle through a distribution passage 40. The plurality of distribution passages 40 are The plunger 38 is placed on the same circumference of the cylinder on which the plunger 38 slides back and forth. As the engine rotates, they are formed at equal intervals corresponding to the injection nozzles of each cylinder of the engine. ing.

[0009] In addition, the drive system is used to change the fuel injection amount according to the engine speed. A ring gear 50 that rotates in synchronization with the shaft 32 and an outer peripheral surface of this ring gear 50. A rotation speed sensor 51, an accelerator sensor 52, and an intake pressure sensor 53 facing the Water temperature sensor 54, intake temperature sensor 55, crank angle sensor 56, electromagnetic spill A valve 58 and a computer 59 are provided (see Japanese Patent Laid-Open No. 64-35046). (see).

0010 Next, the operation will be explained. As in the case of the first prior art, the drive shaft 3 2 rotates, a feed pump 33 supplies fuel into the body 31. Also, Ka The plate 35 rotates and its face cam 36 engages the roller 37. As a result, the plunger 38 fixed to the cam plate 35 rotates and rotates. It reciprocates in the axial direction based on the cam profile of the iscam 36. This plan After the fuel is sucked into the pressurizing chamber 44 by the operation of the jar 38, it is pressurized and flows into the passage. 45, through the discharge port 39, and through the distribution passage 40 to the injection nozzle. Ru.

[0011] However, the change in fuel injection amount depending on the engine rotation speed is different from that of the first conventional technology. Unlike the case, as shown in FIG. , intake pressure sensor 53, water temperature sensor 54, intake temperature sensor 55, and rotation speed sensor. Based on the data from the sensor 51, the target crank angle is calculated and determined. Based on the data from the rank angle sensor 56 and the rotation speed sensor 51, the actual crank determine the crank angle, and then apply an electric current to match the actual crank angle to the target crank angle. This is obtained by controlling the opening and closing of the magnetic spill valve 58.

0012

[Problem that the idea aims to solve]

In the fuel injection device according to the first prior art, the rotation of the drive shaft 32 The rotation of the drive shaft 32 is transmitted to control the fuel injection amount according to the number of fuel injections. The spill ring 4 is controlled by the governor 43 according to the rotation speed of the drive shaft 32. 2 moves to open the spill port 41 into the body 31, and this spill port 41 However, depending on the rotation speed of the drive shaft 32, part of the fuel supply amount can be cut. This is done by

[0013] However, with this fuel injection system, fuel injection is performed from the time of startup to the normal rotation range. The control condition is based on the rotation speed of the drive shaft 32. Since it is only determined mechanically, even if you seek more subtle and appropriate control, the structure will not work. It only becomes more complicated, and the optimum fuel injection amount changes due to changes in intake pressure, intake air temperature, water temperature, etc. The problem with this is that it is impossible to respond to these movements.

[0014] In the electronically controlled fuel injection device according to the second prior art, the drive shaft In the normal rotation range, the fuel injection amount is controlled according to the rotation speed of the computer 58. However, the accelerator sensor 52, intake pressure sensor 53, water temperature sensor 54, and intake temperature The target crank angle is calculated based on the data from the sensor 55 and the rotation speed sensor 51. In addition to calculating the data from the crank angle sensor 56 and the rotation speed sensor 51, Determine the actual crank angle based on the data, and convert this actual crank angle to the target crank angle. obtained by controlling the opening and closing of the electromagnetic spill valve 58 to match the There is.

[0015] However, under this control by the computer 58, the drive system Not only is the rotation speed of the shaft 32 low, but also fluctuations in the rotation speed of the drive shaft 32 is large, so the opening and closing of the electromagnetic spill valve 58 is controlled by the computer 58. The opening timing of the electromagnetic spill valve 58, that is, the opening timing of the electromagnetic spill valve 58, the fuel is released, and the fuel injection is started. The electromagnetic The spill valve 58 is kept closed to inject the maximum amount.

[0016] Therefore, in the second conventional technology, in the normal rotation range, the first conventional technology Although the fuel injection amount is controlled from the time to the normal rotation range, the control conditions are It is only determined mechanically according to the rotation speed of the live shaft 32, so Even if we seek delicate and appropriate control, it will only complicate the structure and reduce intake pressure, intake air temperature, The problem is that it is not possible to respond to changes in the optimal fuel injection amount due to changes in water temperature, etc. However, when starting at low temperatures, the fuel injection amount cannot be controlled. In this case, the electromagnetic spill valve is kept closed and the maximum injection amount is injected. There are problems with poor performance and white or black smoke coming out when starting. This invention is based on the above By solving these problems, optimal fuel injection can be achieved over a wide range from startup to normal rotation range. The objective of this research is to provide an electronically controlled fuel injection device that can obtain a certain amount of fuel injection.

[0017]

[Means to solve the problem]

In order to solve the above problems, the electronically controlled fuel injection device of the present invention has been developed to Equipped with an electromagnetic spill valve whose opening and closing are electronically controlled. In an electronically controlled fuel injection system, a portion of the fuel that is pumped by the plunger A spill port is provided on the plunger to control the amount of fuel pumped. , equal parts on the same circumference of the cylinder side in which this plunger slides back and forth inside. A number of spill holes equal to the number of cylinders are provided at the positions, and as the plunger rotates, the spill holes are When the spill port and the spill hole come to the matching position, the spill hole Controls the amount of fuel pumped by letting some of the fuel escape through the outlet and the fuel injection device internal chamber. The electromagnetic spill valve is kept in the closed position at the time of startup. After the optimal amount of starting fuel is injected, the spill port and spill hole come to the matching position. The relative position of the spill port and the spill hole is determined so as to It is characterized by.

[0018]

[Effect]

The electronically controlled fuel injection device of the present invention is different from the electronically controlled fuel injection device of the prior art. Unlike this, a portion of the fuel pumped by the plunger is released to control the amount of fuel pumped. A spill port is provided in the plunger to control the A number equal to the number of cylinders are placed at equal positions on the same circumference on the cylinder side that slides back and forth. A spill hole is provided, and as the plunger rotates, this spill port and spill hole When the mating position is reached, the spill hole connects the spill port and the fuel injector interior. It is configured to control the amount of fuel pumped by letting a part of the fuel escape through the During operation, the electromagnetic spill valve is kept in the closed position, and after the optimum amount of starting fuel is injected, Adjust the spill port so that the spill port and spill hole are in the matching position. By determining the relative position of the The amount of injection can be obtained.

[0019]

【Example】

FIG. 1 is a system diagram of an embodiment of the present invention. As shown in Figure 1, body 1 , a drive shaft 2 that rotates synchronously with the output shaft of the diesel engine, and a dry It is driven by the fuel tank shaft 2 to suck up fuel from the fuel tank and supply it into the body 1. a feed pump 3 that rotates, and a cam plate 4 that rotates in synchronization with the drive shaft 2. The face cam 5 provided on the end face of this cam plate 4 and the face cam 5 provided on the fixed side. a roller 6 that engages with the face cam 5 of the cam plate 4; The structure includes a plunger 7 that moves in the axial direction according to the lift and pumps the fuel. It has the ability to

[0020] The fuel injection amount is determined by the diameter of the plunger 7 and the profile of the face cam 5. The fuel to be pumped is basically determined by the discharge port 8 and the plunger The rotation of the plunger 7 is placed on the same circumference on the cylinder side in which the plunger 7 slides back and forth inside. As the engine rotates, it is shaped at equal intervals at positions corresponding to the injection nozzles of each cylinder of the engine. It is sent to the injection nozzle through a plurality of distribution passages 9 formed in the same manner.

[0021] In addition, the drive system is used to change the fuel injection amount according to the engine speed. A ring gear 10 that rotates in synchronization with the shaft 2 and an outer peripheral surface of this ring gear 10. The rotation speed sensor 11, the accelerator sensor 12, the intake pressure sensor 13, and the water Temperature sensor 14, intake temperature sensor 15, crank angle sensor 16, and electromagnetic spill valve 18 and an electronic control section 19 equipped with a computer.

The above range of the configuration of this embodiment is the same as that of the electronically controlled fuel injection device according to the prior art. As shown in FIG. 2, in order to maintain the optimum fuel injection amount at startup, the plunger 7 is provided with a spill port 20 that controls the amount of fuel pumped by releasing a portion of the fuel pumped by the plunger 7. Spill holes 21, the number of which is equal to the number of cylinders, are provided at equally divided positions on the same circumference on the cylinder side in which the plunger 7 reciprocates inside the cylinder, and the spill holes 21 are provided in a number equal to the number of cylinders. By releasing a portion of the fuel, the amount of fuel pumped is controlled, and as shown in the timing chart of this embodiment in FIG. 3, (the horizontal axis in FIG. The rotation angle of the drive shaft 2 as a reference, which in electronic control is calculated by the electronic control unit 19 based on data from the ring gear 10 and the rotation speed sensor 11.) Spill angle range θ ₂ ( The spill angle is the rotation angle of the drive shaft 2 when the spill hole 21 releases part of the fuel through the spill port 20 and the fuel injection device inner chamber.) As shown in FIG. The relative position of the spill port 20 and the spill hole 21 is determined so that it is larger than the spill angle range θ ₁ by electronic control at , the electromagnetic spill valve 18 is kept closed so that only the spill port 20 operates.

[0023] Next, the operation will be explained. However, in this example, the electronically controlled type according to the conventional technology The operation of the same component as the fuel injection device is similar to that of the second prior art electronically controlled fuel injection system. Since the operation is the same as that of the fuel injection device, the explanation will be omitted, and the parts constituting the features of this embodiment described above will be omitted. Only the operation will be explained.

[0024] The electronically controlled fuel injection device of this embodiment is a conventional electronically controlled fuel injection device. It is superior in controlling fuel injection at the time of starting compared to a conventional engine. That is, the conventional technology As mentioned above, under the control by the computer 58, when starting at a low temperature, the driver Not only is the rotation speed of the live shaft 32 low, but also the rotation speed of the drive shaft 32 is low. Since the number of fluctuations is large, the electromagnetic spill valve 58 is used for fluctuation control by the computer 58. The valve opening timing of the electromagnetic spill valve 58 cannot be followed, that is, the opening timing of the electromagnetic spill valve 58 cannot be followed; If fuel injection is stopped too early, fuel shortage problems may occur. Then, the electromagnetic spill valve 58 is kept closed to inject the maximum injection amount. . As a result, starting performance is poor and white or black smoke is emitted when starting. In contrast, this implementation In the example electronically controlled fuel injection system, at the time of starting, the electronic control section 19 is activated in FIG. Since the electromagnetic spill valve 18 is kept closed, only the spill port 20 is connected to the plunger 7. It serves to release part of the fuel that is being pumped out.

[0025] In this case, the operation of the electronically controlled fuel injection system of this embodiment at the time of startup will be explained with reference to FIGS. 2 and 3. As described above, since the electronic control unit 19 keeps the electromagnetic spill valve 18 closed, fuel is continuously supplied from the feed hole 22. Then, the lift of the plunger 7 decreases, and the fuel is sucked into the pressurizing chamber 24 in the angular range in which the suction grooves 23 corresponding to the cylinders of the engine communicate with the feed hole 22 . When the lift of the plunger 7 increases, the suction groove 23 comes out of the feed hole 22, and the discharge port 8 communicates with the distribution passage 9, the fuel flows through the distribution passage 9 to the injection nozzle (not shown). sent to. The angle shown in FIG. 3 corresponds to the spill angle range θ ₁ by electronic control in the normal rotation range (the control of the spill angle by the governor 43 and spill ring 42 in the first prior art also corresponds mainly to this range θ ₁ ). .) When the size becomes larger, the spill hole 21 communicates with the spill port 20, so the fuel escapes into the body 1 and fuel injection stops. If the angle at which this spill hole 21 communicates with the spill port 20 is matched to the engine characteristics at the time of startup, an appropriate injection amount can be obtained at the time of startup, the startability is good, and there is no white smoke or black smoke at the time of startup.

[0026] The present invention is not limited to the above-mentioned embodiments, and various embodiments are possible. The electronic control method is automatic. Spill ports and spill holes can be designed freely according to the purpose.

[0027]

[Effect of the idea]

The electronically controlled fuel injection device of the present invention is a conventional electronically controlled fuel injection device. However, when starting, the fuel injection amount cannot be selected optimally, resulting in poor starting performance. There was a problem with white smoke and black smoke, but when starting, the optimal fuel Since the injection amount can be selected, it has good starting performance and eliminates white and black smoke. .

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of the present invention.

2 is a partially detailed view of the embodiment of FIG. 1; FIG.

FIG. 3 is a timing diagram of the embodiment of FIG. 1;

FIG. 4 is a longitudinal sectional front view of the first prior art.

FIG. 5 is a system diagram of a second prior art.

FIG. 6 is a system diagram of electronic control according to a second prior art.

[Explanation of symbols]

20 Spill port 21 Spill hole

Claims (1)

[Scope of utility model registration request] [Claim 1] By electronic control in the normal rotation range,
In an electronically controlled fuel injection device equipped with an electromagnetic spill valve whose opening/closing is controlled, a spill port is provided on the plunger to control the amount of fuel pumped by releasing a portion of the fuel pumped by the plunger. A number of spill holes equal to the number of cylinders are provided at equally divided positions on the same circumference on the same circumference of the cylinder side in which the plunger slides back and forth, and as the plunger rotates, the spill ports and spill holes match the positions. The spill hole is configured to control the amount of fuel pumped by letting a part of the fuel escape through the spill port and the fuel injection device inner chamber, and at the time of starting, the electromagnetic spill valve is set to the closed position. and the relative position of the spill port and the spill hole is determined so that the spill port and the spill hole come to the coincident position after an optimum amount of starting fuel is injected. Controlled fuel injection system.