JP2007046467A - Method and device for starting performance inspection of injector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for starting performance inspection of an injector allowing filling of liquid in every corner of a liquid circuit formed in an injector. <P>SOLUTION: The method for starting performance inspection of the injector filling fluid in the injector 100 provided with a fluid circuit having a supply passage opening 181 on one end and a discharge passage opening 191 on another end, an injection hole 112 provided in a middle of the fluid circuit, a nozzle needle 120 stored in the fluid circuit and opening and closing the injection hole 112, and an actuator changing a circulation route of fluid in the fluid circuit or fluid pressure to open and close the nozzle needle 120, comprises a first high pressure fluid supply process (step S122) supplying high pressure fluid into the fluid circuit from the supply passage opening 181, and a second high pressure fluid supply process (step S123) supplying high pressure fluid into the fluid circuit from the discharge passage opening 191. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and apparatus for initiating performance inspection of an injector for filling a fluid into an injector that is performed at the beginning of performance inspection of the injector after manufacturing the injector of an internal combustion engine for an automobile.

  After manufacturing an injector for an automobile internal combustion engine, when the injector performance inspection for inspecting the performance of the injector is started, an operation of filling the fluid into the fluid circuit of the injector is performed. Conventionally, a performance inspection starting method and apparatus for performing the work have been proposed (see Patent Document 1).

The performance inspection starting method and the apparatus thereof are configured such that a negative pressure generating means connected to the discharge passage opening side (return side) of the injector first makes the inside of the fluid circuit of the injector a negative pressure state, and then the supply passage opening of the injector The fluid circuit is filled with fluid by supplying pressurized fluid into the fluid circuit from the fluid supply unit connected to the side.
JP 2002-242800 A

  There are various types of injectors to be inspected by the performance inspection device, and there are also various mechanisms for operating nozzle needles provided in the injectors for opening and closing the nozzle holes. For example, there is an injector of a type using a piezo element as an actuator used in a mechanism for operating the nozzle needle (hereinafter referred to as a piezo injector).

  This piezo injector utilizes the fact that the piezo element itself is displaced by energization, and this displacement changes the flow path of the fluid in the fluid circuit to control the balance of pressure applied to the nozzle needle, thereby opening and closing the nozzle hole. is doing. However, since the displacement amount of the piezo element is very small, the injector is provided with a hydraulic displacement enlarging mechanism in the fluid circuit. The nozzle needle is operated by changing the flow path with the displacement enlarged by the displacement magnifying mechanism.

  The displacement enlarging mechanism is composed of a piston having two different diameters and a hydraulic chamber formed between the pistons. Since the two pistons seal the hydraulic chamber, the gap between the piston and the wall surface guiding the piston is very small. In addition, the hydraulic chamber is located on the discharge passage side of the fluid circuit.

  When the piezo injector is filled with fluid by the method and apparatus for initiating performance inspection, the fluid circuit is not sufficiently filled with fluid. In particular, the fluid pressure chamber is not filled with fluid, and an actuator (such as a piezo element is movable). Even if the member is operated, the displacement of the actuator (movable member such as a piezo element) is not transmitted, and the nozzle needle does not operate. For this reason, the problem that the fluid is not injected from the nozzle hole and the next inspection process cannot be performed occurs.

  The present invention has been made in view of the above points, and the purpose thereof is the performance of an injector capable of filling a fluid to every corner of a fluid circuit formed in the injector regardless of the type of the injector. An object of the present invention is to provide an inspection start method and an apparatus therefor.

In order to achieve the above object, according to the injector performance inspection starting method according to claim 1, a fluid circuit having a supply passage port at one end and a discharge passage port at the other end is provided in the middle of the fluid circuit. A nozzle hole that is accommodated in the fluid circuit, opens and closes the nozzle hole, and an actuator that changes a fluid passage or fluid pressure in the fluid circuit so as to open and close the nozzle needle; A method for starting performance inspection of an injector for filling a fluid in an injector comprising:
A first high-pressure fluid supply step for supplying high-pressure fluid into the fluid circuit from the supply passage port; and a second high-pressure fluid supply step for supplying high-pressure fluid into the fluid circuit from the discharge passage port. Yes.

  According to this method, since the high pressure fluid is supplied not only from the supply passage port but also from the discharge passage port, the fluid can be filled into the fluid circuit of the injector. Further, according to this method, since the high-pressure fluid is supplied from both passage openings, the fluid filling operation can be completed in a shorter time than in the prior art. The actuator referred to here is not only one that changes the fluid path or fluid pressure of the fluid circuit by energizing, such as an electromagnetic valve or a piezo element, but also inside the fluid circuit to open and close the nozzle needle. Also includes parts that change the fluid path and fluid pressure.

  According to the injector performance inspection start method of the second aspect, the first high-pressure fluid supply step and the second high-pressure fluid supply step are performed substantially simultaneously. According to this method, since the high-pressure fluid is supplied from both passage openings almost simultaneously, the fluid filling operation is completed in a shorter time.

  According to the injector performance test starting method according to claim 3, the injector includes a negative pressure step for setting the inside of the fluid circuit to a negative pressure state, and the negative pressure step is performed before the first high pressure supply step and the second high pressure supply step. It is characterized by being implemented. According to this method, since the inside of the fluid circuit of the injector is brought into a negative pressure state before entering the first and second high pressure supply steps, the relative pressure of the high pressure fluid supplied by the first and second high pressure supply steps is reduced. growing. When a high pressure fluid is supplied in a state where the relative pressure is increased, the high pressure fluid spreads through a minute gap in the fluid circuit, and the fluid is easily filled to every corner of the fluid circuit.

  According to the injector performance inspection start method of the fourth aspect, the negative pressure step, the first high-pressure fluid supply step and the second high-pressure fluid supply step are alternately and repeatedly performed. If the fluid circuit is complicatedly installed or there is a portion having a minute gap in the fluid circuit, it is difficult to completely fill the fluid circuit with a single high-pressure fluid supply process. A small amount of gas remains in the fluid circuit. According to this method, since the negative pressure process and the first and second high-pressure fluid supply processes are alternately repeated, the gas remaining in the fluid circuit can be removed in a short time, Fluid can be filled to every corner of the fluid circuit.

  According to the injector performance test starting method of the fifth aspect, the actuator is provided with an actuator operation step for operating the actuator so as to change the fluid flow path or the fluid pressure in the fluid circuit. According to this method, when the actuator operates, the fluid is likely to be dragged into the gap between the actuator and the wall surface that guides the actuator. Thereby, the fluid is also filled in the gap and the like.

  According to the injector performance inspection start method of the sixth aspect, the actuator operation step is performed during the first high-pressure fluid supply step or the second high-pressure fluid supply step. Parts constituting the injector, in particular, actuators, nozzle needles, and the like are manufactured on the assumption that the fluid circuit is filled with fluid. Therefore, if the actuator or the nozzle needle is operated in a state where the fluid circuit is not filled with fluid, there is a possibility that the actuator, the nozzle needle, or a guide wall for guiding them may be worn.

  On the other hand, according to the injector performance inspection start method according to claim 6, since the actuator operation step is performed during the first or second high-pressure fluid supply step, wear of the actuator and the nozzle needle is minimized. be able to.

  According to the injector performance inspection start method according to claim 7, when the actuator operation step is performed, it is determined that the fluid filling into the injector is completed when the fluid is ejected from the nozzle hole. It is said. Depending on the type of injector, for example, a piezo injector or the like has a hydraulic displacement enlarging mechanism formed in the fluid circuit as described above, and this enlarging mechanism is not sufficiently filled with fluid. Even if the actuator (piezo element) is operated, fluid cannot be ejected.

  According to this method, the fact that the fluid has been injected from the nozzle hole is used as a criterion for determining whether or not the fluid has been filled into the injector. Therefore, even if the injector is of a type such as a piezo injector, the completion of fluid filling is properly determined. can do.

  The operation and effect of the injector performance inspection start device according to claims 8 to 14 are the same as the operation and effect of the injector performance inspection start method according to claims 1 to 7, and the description thereof is omitted. To do.

  Hereinafter, an injector performance inspection starting method and apparatus according to an embodiment of the present invention will be described with reference to the drawings. First, an outline of the injector performance inspection apparatus will be described. Next, the injector 100 inspected by the inspection apparatus 1 will be described.

  FIG. 1 is an overall configuration diagram of a performance inspection device (hereinafter referred to as an inspection device) 1 of an injector 100. The inspection apparatus 1 has a function of performing a performance inspection start process and a running operation process in which a fluid is filled in the fluid circuit of the injector 100 after the injector 100 is manufactured and before the performance inspection of the injector 100 is performed. The inspection apparatus 1 includes a work holding unit 2, a supply-side high-pressure fluid supply unit 3, a discharge-side high-pressure fluid supply unit 4, a negative pressure unit 5, a pressure holding unit 6, a flow meter 7, a tank 13, and a control device 14. .

  The work holding unit 2 is a jig that holds an injector 100 that is an object to be inspected. The injector 100 is generally provided with a high-pressure passage port 181 as a supply passage port for introducing the fluid to be injected into the injector 100 and a return passage port 191 as a discharge passage port for discharging the fluid that has not been used for injection. ing. Wiring from the control device 14 is connected to the injector 100, and the control device 14 transmits a drive signal to the injector 100 to drive the injector 100. In the injector 100, a fluid circuit is formed between the high pressure passage port 181 and the return passage port 191. The operation of the injector 100 and the fluid circuit will be described later.

  The supply-side high-pressure fluid supply unit 3 corresponds to the first high-pressure fluid supply means described in the claims, and is connected to the high-pressure passage port 181 of the injector 100 via the first supply pipe 8 as the first pipe. The supply unit 3 supplies high-pressure fluid from the high-pressure passage port 181 to the fluid circuit of the injector 100 and fills the fluid. Specifically, the supply unit 3 includes a first supply pump 31 and a first high pressure control valve 32.

  The first supply pump 31 is, for example, a high pressure pump that pressurizes the fluid sucked from the tank 13 and discharges the fluid to the first supply pipe 8. The type of the pump is not limited to this type, and may be a pressure accumulator capable of accumulating high-pressure fluid. The first high-pressure control valve 32 is a valve that is provided in the middle of the first supply pipe 8 and controls whether the high-pressure fluid discharged from the pump 31 is supplied to the high-pressure passage port 181 by opening and closing the valve. is there. The pressurization and discharge operation of the pump 31 and the operation of the control valve 32 are controlled by a control signal transmitted from the control device 14. Hereinafter, the high-pressure fluid is appropriately referred to as high-pressure fuel, and the fluid is appropriately referred to as fuel.

  The discharge-side high-pressure fluid supply unit 4 corresponds to the second high-pressure fluid supply means described in the claims, and is connected to the return passage port 191 of the injector 100 via the second supply pipe 9 as the second pipe. The supply unit 4 supplies high-pressure fluid from the return passage port 191 to the fluid circuit of the injector 100 and fills the fluid. Specifically, the supply unit 4 includes a second supply pump 41 and a second high-pressure control valve 42.

  The second supply pump 41 is, for example, a high pressure pump that pressurizes the fluid sucked from the tank 13 and discharges the fluid to the second supply pipe 9. The type of the pump is not limited to this type, and may be a pressure accumulator capable of accumulating high-pressure fluid. The second high-pressure control valve 42 is provided in the middle of the second supply pipe 9 and controls whether or not the high-pressure fluid discharged from the pump 41 is supplied to the return passage port 191. The pressurization and discharge operation of the pump 41 and the operation of the control valve 42 are controlled by a control signal transmitted from the control device 14.

  The negative pressure section 5 corresponds to the negative pressure generating means described in the claims, and is provided through the negative pressure supply pipe 10 and the second supply pipe 9 as a third pipe branched from the second supply pipe 9. It is connected to the return passage port 191. The negative pressure part 5 makes the inside of the fluid circuit of the injector 100 a negative pressure state. Specifically, the negative pressure unit 5 includes an air supply pump 51, a pump control valve 52, an ejector 53, and a negative pressure control valve 54.

  The negative pressure supply pipe 10 has one end connected to the second supply pipe 9 and the other end connected to the tank 13. The negative pressure control valve 54 and the ejector 53 are provided in the middle of the negative pressure supply pipe 10 in the order of the negative pressure control valve 54 and the ejector 53 from the second supply pipe 9 side. As shown in the figure, the air supply pump 51 and the pump control valve 52 are connected to an ejector 53.

  The ejector 53 is a negative pressure generating device that uses the kinetic energy of the fluid. By providing the ejector 53 in the negative pressure supply pipe 10 and operating the ejector 53, the air in the fluid circuit of the injector 100 or the fluid in the fluid circuit is converted. It can be removed and put into a negative pressure state.

  The air supply pump 51 is for supplying high-pressure air to the ejector 53. Accordingly, the ejector 53 can generate a negative pressure in the negative pressure supply pipe 10 by using a part of the kinetic energy of the supplied high-pressure air as energy for generating a negative pressure.

  The pump control valve 52 is a valve that controls the supply of high-pressure air supplied from the air supply pump 51 to the ejector 53. The negative pressure control valve 54 is a valve that controls whether or not the negative pressure generated in the ejector 53 is supplied to the injector 100. The discharge operation of the high-pressure air of the pump 51 and the operations of the pump control valve 52 and the negative pressure control valve 54 are controlled by a control signal transmitted from the control device 14.

  The pressure holding unit 6 is connected to a return passage port 191 of the injector 100 through a return pipe 11 branched from the second supply pipe 9 and the second supply pipe 9. The pressure holding unit 6 holds the pressure in the second supply pipe 9 at a predetermined pressure. Specifically, it consists of a check valve 61 and a pressure control valve 62.

  The return pipe 11 has one end connected to the second supply pipe 9 and the other end connected to the tank 13. The check valve 61 is a valve that allows only the flow from the second supply pipe 9, and the pressure control valve 62 supplies the fluid from the second supply pipe 9 to the tank 13 when a pressure higher than a predetermined pressure is applied. It is a valve to return to.

  The flow meter 7 corresponds to the fluid sensing means described in the claims, and has one end connected to the work holding unit 2 and the other end connected to the tank 13 as a circulation pipe as a fourth pipe. 12 is provided in the middle. The flow meter 7 is for sensing fluid ejected from the injector 100 in the work holding unit 2. In the present embodiment, the flow meter 7 is used, but it is sufficient that it can sense at least that the fluid has flown through the circulation pipe 12. The flow meter 7 transmits to the control device 14 that a fluid is sensed or a signal corresponding to the fluid flow rate.

  The control device 14 includes a CPU that performs various arithmetic processes, a storage device (memory such as ROM, standby RAM, EEPROM, and RAM) that stores various programs and data, an input circuit, an output circuit, a power supply circuit, and various devices (injector 100). , Pumps 31, 41, 51, valves 32, 42, 52, 54).

  Next, the structure and operation of the injector 100 as an object to be inspected will be described with reference to FIGS. FIG. 6 is a cross-sectional view of the injector 100 showing a state when the injection is stopped. FIG. 7 is a cross-sectional view of the injector 100 showing a state during injection.

  As shown in FIG. 6, the injector 100 is applied to, for example, an internal combustion engine (hereinafter abbreviated as “engine”) having a common rail fuel injection system, and provided in a one-to-one correspondence with each cylinder of the engine. It is done. The injector 100 injects fuel supplied from the common rail during a predetermined period under the control of an ECU (not shown) (not shown).

  The injector 100 includes a nozzle unit 101 and a back pressure control unit 102. The injector 100 has a rod-like body 110, and a hole for housing each component constituting each of the parts 101 and 102, and a passage or space through which fuel as a fluid circuit according to the claims flows. Here, the upper and lower sides of the injector 100 will be described corresponding to the upper and lower sides of the drawing.

  A first vertical hole 111 is formed in the nozzle portion 101 of the body 110. As shown in FIG. 6, the space of the first vertical hole 111 is closed, and a nozzle hole 112 penetrating the body 110 is formed at the lower end thereof. A sheet 113 is formed on the inner wall of the first vertical hole 111 on the upper side of the nozzle hole 112.

  In the first vertical hole 111, the nozzle needle 120 and the first spring 161 are accommodated. The nozzle needle 120 is accommodated so as to be able to reciprocate up and down in the first vertical hole 111. The nozzle needle 120 has a large-diameter portion 121 on the upper side and a small-diameter portion 122 having a smaller diameter than the large-diameter portion 121 on the lower side. The large diameter portion 121 is slidably supported in the first vertical hole 111.

  By accommodating the large-diameter portion 121 in the first vertical hole 111, the space in the first vertical hole 111 is partitioned. The upper space becomes the back pressure chamber 171, and the lower space becomes the oil reservoir chamber 170. The body 110 is formed with a high pressure passage 180 for supplying high pressure fuel supplied from the high pressure passage port 181 to the back pressure chamber 171 and the oil sump chamber 170. The nozzle needle 120 receives the pressure of the high-pressure fuel in the back pressure chamber 171 and the oil reservoir chamber 170.

  A first spring 161 is accommodated in the back pressure chamber 171. One end of the first spring 161 is supported above the back pressure chamber 171, and the other end is supported by the large diameter portion 121. The spring 161 always applies a downward biasing force to the nozzle needle 120. The movement of the nozzle needle 120 is determined by the balance of the pressure in the back pressure chamber 171, the pressure in the oil reservoir chamber 170, and the biasing force of the first spring 161.

  A second vertical hole 114 is formed in the back pressure control unit 102 of the body 110. As shown in FIG. 6, the second vertical hole 114 is formed so that the flow path of the fluid circuit and the pressure in the circuit can be changed by the operation of the components accommodated therein and the components accommodated therein. Yes.

  As shown in FIG. 6, the second vertical hole 114 accommodates the second spring 162, the valve needle 130, the third spring 163, the large-diameter piston 140, the fourth spring 164, and the piezo stack 150 in order from the bottom. Yes.

  The valve needle 130 and the large-diameter piston 140 are accommodated so as to reciprocate up and down in the second vertical hole 114. The valve needle 130 includes a sliding piston 133, a valve body 132, and a small-diameter piston 131 in order from the lower side. As shown in FIG. 6, each part is connected by a joint, and each part reciprocates integrally. The sliding piston 133 and the small diameter piston 131 are slidably supported in the second vertical hole 114.

  The sliding piston 133 defines a space in the second vertical hole 114, forms a spring chamber 175 below the sliding piston 133, and forms a sliding piston chamber 179 on the upper side. The sliding piston chamber 179 is connected to the high-pressure passage 180 so that high-pressure fuel is supplied. A second spring 162 is accommodated in the spring chamber 175. One end of the second spring 162 is supported below the spring chamber 162, and the other end is supported by the sliding piston 133. The spring 162 always applies an upward biasing force to the sliding piston 133.

  The small-diameter piston 131 defines a space in the second vertical hole 114, forms a small-diameter piston chamber 177 below the small-diameter piston 131, and forms a hydraulic chamber 176 above it. The body 110 is formed with a return communication passage 192 for discharging the fuel in the spring chamber 175 and the small diameter piston chamber 177 from the injector 100.

  As shown in FIG. 6, a valve chamber 172 in which the valve body 132 is accommodated is formed between the sliding piston chamber 179 and the small diameter piston chamber 177. A high-pressure port 174 is formed at the boundary between the sliding piston chamber 179 and the valve chamber 172, and a return port 173 is formed at the boundary between the small-diameter piston chamber 177 and the valve chamber 172. The body 110 is formed with a high-pressure communication path 182 having one end connected to the back pressure chamber 171 and the other end connected to the valve chamber 172.

  The valve body 132 reciprocates up and down to open and close the ports 173 and 174 and change the flow path of the high-pressure fuel. When the valve body 132 moves upward, the high-pressure port 174 is opened and the return port 173 is closed. As a result, the high pressure fuel in the sliding piston chamber 179 flows into the valve chamber 172 via the high pressure port 174 and is supplied to the back pressure chamber 171 via the high pressure communication path 182. On the contrary, when moving downward, the high-pressure port 174 is closed and the return port 173 is opened. As a result, the high-pressure fuel in the back pressure chamber 171 and the valve chamber 172 is discharged to the return communication path 192 via the return port 173 and discharged from the injector 100.

  A large-diameter piston 140 having a diameter larger than that of the small-diameter piston 131 is accommodated above the hydraulic chamber 176 in the second vertical hole 114. The large-diameter piston 140 defines a space in the second vertical hole 114, forms a hydraulic chamber 176 on the lower side of the large-diameter piston 140, and forms a stack chamber 178 on the upper side. A third spring 163 is accommodated in the hydraulic chamber 176. The third spring 163 has one end supported by the large diameter piston 140 and the other end supported by the small diameter piston 131. The spring 163 always applies a biasing force to the large-diameter piston 140 and the small-diameter piston 131 in a direction in which the pistons 140 and 131 are separated from each other.

  The stack chamber 178 is connected to the end of the return communication path 192 and the end of the return path 190. The return path 190 has a return path port 191. The fuel discharged to the stack chamber 178 via the return communication path 192 is discharged from the injector 100 via the return path 190 and the return path port 191.

  A piezo stack 150 as a piezo element is accommodated in the stack chamber 178 located further above the large-diameter piston 140. The piezo stack 150 is a known structure having a capacitor structure in which piezoelectric ceramic layers such as PZT and electrode layers are alternately stacked. When this piezo stack 150 is charged and discharged, it expands and contracts in the vertical direction. The upper end portion of the large-diameter piston 140 is in contact with the lower end portion of the piezo stack 150, and the expansion and contraction of the piezo stack 150 is transmitted to the large-diameter piston 140. A fourth spring 164 is provided at the lower end of the piezo stack 150. The spring 164 applies an initial upward load to the piezo stack 150.

  The hydraulic chamber 176 functions as a part of the displacement enlarging mechanism because the large-diameter piston 140 is provided on the upper side and the small-diameter piston 131 is provided on the lower side. Since the large-diameter piston 140, the small-diameter piston 131, and the hydraulic chamber 176 are arranged as shown in the figure, the displacement of the large-diameter piston 140 is transmitted to the small-diameter piston 131 via the fluid in the hydraulic chamber 176. At that time, the displacement of the small diameter piston 131 is larger than the input displacement. The piezo stack 150 has the characteristics that the operation speed is high and the amount of expansion and contraction is very small. By using the displacement enlarging mechanism as described above, the expansion / contraction amount of the piezo stack 150 can be increased and transmitted to the valve body 132. Thereby, the distribution route of high-pressure fuel can be changed.

  Next, the operation of the components housed in the injector 100 and the flow of fuel flowing through the passage will be described. Here, the operation of the injector 100 in a state in which various pressure chambers (fluid circuit) and various passages (fluid circuit) are filled with fluid (fuel) will be described.

  As shown in FIG. 6, when the piezo stack 150 is in a discharge state, the valve needle 130 tries to move upward due to the balance between the urging forces of the second and third springs 162 and 163 applied to the valve needle 130 and the fuel pressure. The valve body 132 closes the return port 173. As a result, the high pressure fuel in the sliding piston chamber 179 is supplied to the back pressure chamber 171 via the high pressure communication path 182.

  The high-pressure fuel supplied via the high-pressure passage 180 is supplied to the back pressure chamber 171 and the oil reservoir chamber 170 of the nozzle needle 120. At this time, the nozzle needle 120 is about to move downward due to the balance of the fuel pressure in the back pressure chamber 171 and the oil reservoir chamber 170 and the biasing force of the first spring 161. Then, the tip of the small diameter portion 122 of the nozzle needle 120 is seated on the seat 113, and the fuel in the oil reservoir chamber 170 is not injected from the injection hole 112.

  As shown in FIG. 7, when the piezo stack 150 is charged and the piezo stack 150 itself extends, the large-diameter piston 140 is displaced by an amount corresponding to the extension amount. Then, the fuel in the hydraulic chamber 176 is compressed, and the pressure is transmitted to the small diameter piston 131. Since both the pistons 140 and 131 and the hydraulic chamber 176 serve as a displacement expansion mechanism, the displacement of the small diameter piston 131 is expanded.

  The valve element 132 of the valve needle 130 moves integrally with the small diameter piston 131 in the downward direction. Then, the valve body 132 opens the return port 173 and closes the high-pressure port 174. At this time, the high-pressure fuel in the back pressure chamber 171 and the valve chamber 172 is discharged to the return communication path 192 via the return port 173.

  Since the high-pressure fuel in the back pressure chamber 171 is discharged to the return communication passage 192, the pressure in the back pressure chamber 171 becomes lower than the pressure in the oil reservoir chamber 170, and the nozzle needle 120 moves upward. When the nozzle needle 120 moves upward, the tip of the small diameter portion 122 of the nozzle needle 120 is separated from the seat 113. When the tip of the small diameter portion 122 is separated from the seat 113, the fuel in the oil sump chamber 170 is injected from the injection hole 112.

  When the piezo stack 150 is discharged again, the piezo stack 150 contracts, the valve needle 130 moves upward, the valve element 132 closes the return port 173, and opens the high-pressure port 174. The pressure in the back pressure chamber 171 increases, the nozzle needle 120 moves downward, and the tip of the small diameter portion 122 is seated on the seat 113. Since the tip of the small diameter portion 122 is seated on the seat 113, fuel injection from the nozzle hole 112 is stopped.

  The various pressure chambers 170, 171, 172, 175, 176, 177, 178 and 179 and the various passages 180, 182, 190 and 192 of the injector 100 correspond to the fluid circuit described in the claims, and the piezo stack 150 The large-diameter piston 140 and the valve needle 130 correspond to the actuator described in the claims. When referring to the various pressure chambers and the various passages, it is expressed as a fluid circuit.

  The injector 100 is characterized by a piezo stack 150 and a hydraulic displacement enlarging mechanism for enlarging the displacement amount of the piezo stack 150. If this type of injector 100 is installed in a conventional inspection apparatus and fluid is filled in the fluid circuit before the performance inspection, the fluid may not be filled to every corner of the fluid circuit. In particular, the hydraulic chamber 176 may not be filled with fluid.

  As shown in FIG. 6, the hydraulic chamber 176 is in a closed space between the large-diameter piston 140 and the small-diameter piston 131 and is far from the high-pressure passage port 181. In a state where the valve body 132 closes the return port 173, the high-pressure fluid that flows in from the high-pressure passage port 181 causes the sliding gap of the sliding piston 133, the return communication passage 192, the small-diameter piston chamber 177, and the stack chamber 178. Therefore, it is necessary to flow in through a sliding gap between both pistons 131 and 140, and it is very difficult to flow high-pressure fuel into the hydraulic chamber 176. The sliding gap refers to the large-diameter piston 140, the various pistons 131 and 133 of the valve needle 130, the large-diameter portion 121 of the nozzle needle 120, and the first and second vertical holes 111 and 114 in which these components slide. It is a gap with the wall surface.

  In a state where the fluid pressure chamber 176 is not filled with fluid (a state where gas is contained), the displacement of the piezo stack 150 and the large diameter piston 140 is not transmitted to the small diameter piston 131. Since the valve body 132 is integrated with the small-diameter piston 131, the valve body 132 does not operate even though the piezo stack 150 is operating. As a result, since the pressure in the back pressure chamber 171 cannot be controlled, the nozzle needle 120 does not operate and fuel cannot be injected from the injector 100. If the injector 100 cannot be operated, the performance inspection of the injector 100 cannot be performed.

  If the inspection apparatus 1 described earlier in this embodiment is used and the injector 100 of the above type is filled with fluid by the inspection start method described below, the fluid is filled to every corner of the fluid circuit of the injector 100. Can be made.

  Next, a procedure for installing the injector 100 in the performance inspection apparatus 1 and inspecting the performance of the injector 100 will be described with reference to FIGS. FIG. 2 is a flowchart showing a flow of performance inspection of the injector 100. FIG. 3 is a flowchart showing the flow of the performance inspection start process in FIG. FIG. 4 is a flowchart showing the flow of the negative pressure process in FIG. FIG. 5 is a flowchart showing the flow of the high-pressure fluid supply process in FIG.

  As shown in FIG. 2, the performance inspection of the injector 100 includes three processes, a performance inspection start process, a running operation process, and a performance inspection process. In step S1, a performance inspection start process is executed. In this step, an injector 100 as an object to be inspected is held on the work holding unit 2, and various pipes 8, 9, 10, 11, 12 are connected as shown in FIG. Then, the fluid circuit of the injector 100 is filled with high-pressure fluid. Specifically, this high-pressure fluid is a test oil equivalent to light oil.

  After the injector 100 is filled with the high-pressure fluid, in step S2, the control device 14 performs the running operation of the injector 100. The running operation is performed to clean the fluid circuit of the injector 100 and raise the temperature of the injector 100 to a temperature suitable for performance inspection. Specifically, the temperature is measured by measuring the temperature of the fluid discharged from the return passage port 191 of the injector 100.

  In step S <b> 3, the control device 14 performs a performance test of the injector 100 such as an injection amount and an injection rate. Here, detailed description of the performance inspection items is omitted.

  Next, the performance inspection start process in step S1, which is a characteristic part of the present invention, will be described in detail. As shown in FIG. 3, the performance inspection start process includes three processes: a negative pressure process, a high-pressure fluid supply process, and a performance inspection start process completion confirmation process.

  In step S11, the control device 14 performs a negative pressure process. Specifically, as shown in FIG. 4, the control device 14 stops the first and second supply pumps 31 and 41 and closes the first and second high-pressure control valves 32 and 42 in step S111. The actuator (piezo stack 150, valve needle 130) is stopped.

  Subsequently, in step S112, the control device 14 operates the air supply pump 51, opens the pump control valve 52, and opens the negative pressure control valve 54. Thereby, the ejector 53 generates a negative pressure in the negative pressure supply pipe 10. At this time, the negative pressure portion 5 and the return passage port 191 are connected via the negative pressure supply pipe 10 and the second supply pipe 9. This state corresponds to the second connection state described in the claims. Since the negative pressure control valve 54 is open, air in the fluid circuit of the injector 100 is removed from the return passage port 191 by this negative pressure, and the fluid circuit is in a negative pressure state. Thereafter, the process proceeds to step S12 in FIG.

  Next, in step S12, the control device 14 performs a high-pressure fluid supply process. Specifically, as shown in FIG. 5, the control device 14 closes the negative pressure control valve 54 and the pump control valve 52 and stops the air supply pump 51 in step S121. The negative pressure state in the fluid circuit of the injector 100 is maintained.

  Next, the control apparatus 14 operates the 1st supply pump 31 and opens the 1st high pressure control valve 32 in step S122. Then, the high-pressure fluid generated by the first supply pump 31 is supplied to the fluid circuit via the high-pressure passage port 181 of the injector 100. The process in this step corresponds to the first high-pressure fluid supply process described in the claims.

  Next, the control device 14 operates the second supply pump 41 and opens the second high-pressure control valve 42 in step S123. Then, the high-pressure fluid generated by the second supply pump 41 is supplied to the fluid circuit via the return passage port 191 of the injector 100. The process in this step corresponds to the second high-pressure fluid supply process described in the claims. At this time, the discharge-side high-pressure fluid supply unit 4 and the return passage port 191 are connected via the second supply pipe 9. This state corresponds to the first connection state described in the claims.

  The first and second connection states are switched by the negative pressure control valve 54 and the second high pressure control valve 42. Therefore, these valves 54 and 42 correspond to the switching means described in the claims. Instead of providing the valves 42 and 54 in each of the second supply pipe 9 and the negative pressure supply pipe 10, a three-way valve may be provided in a connection portion between the second supply pipe 9 and the negative pressure supply pipe 10. According to this, switching of the first and second connection states can be controlled by one valve.

  As described above, in steps S122 and S123, devices that generate high-pressure fluid on both sides of the high-pressure passage port 181 and the return passage port 191 of the injector 100 (supply-side high-pressure fluid supply unit 3, discharge-side high-pressure fluid supply unit 4). The high pressure fluid is supplied from the supply parts 3 and 4, so that even the injector 100 having the hydraulic pressure chamber 176 can be filled with the fluid. The high-pressure fluid supplied from the return passage port 191 passes through the return passage 190, the stack chamber 178, the sliding clearance of the large-diameter piston 140, or the return passage 190, the return communication passage 192, the small-diameter piston chamber 177, and the small-diameter piston. It is supplied to the hydraulic chamber 176 through a sliding gap with 131.

  The steps S122 and S123 may be performed substantially simultaneously. If these steps are performed substantially simultaneously, the fluid filling time of the fluid circuit of the injector 100 is shortened.

  In the present embodiment, before the step of supplying the high-pressure fluid in steps S122 and S123, the air in the fluid circuit (including the hydraulic pressure chamber 176) is removed in steps S111 to S113 so as to be in a negative pressure state. Therefore, since the relative pressure between the supplied high-pressure fluid and the pressure in the fluid circuit is increased, it is easy to fill the minute gap (sliding gap) in the fluid circuit with the high-pressure fluid.

  Thereafter, in step S124, the control device 14 operates the first and second supply pumps 31 and 41 to open the first and second high-pressure control valves 32 and 42, and the actuator (piezo stack 150, valve needle). 130) is activated. If the fluid pressure chamber 176 is filled with fluid to some extent, the piezo stack 150 and the valve needle 130 start operating. Since the details of the operation of these components have been described above, the description thereof is omitted here. The process in this step corresponds to the actuator operation process described in the claims.

  Then, the fluid is easily drawn into the sliding gap between the valve needle 130 and the nozzle needle 120, and the gap is also filled with the fluid. Thereafter, the process proceeds to step S13 in FIG.

  Parts constituting the injector 100, in particular, the actuator and the nozzle needle 120 are manufactured on the assumption that the fluid circuit is filled with fluid. Therefore, if the actuator or the nozzle needle 120 is operated in a state where the fluid circuit is not filled with fluid, the actuator or the nozzle needle 120 or the first and second vertical holes 111 and 114 that guide them may be worn. There is.

  In the present embodiment, the process of step S124 is performed while the first and second supply pumps 31 and 41 are operated and the first and second high-pressure control valves 32 and 42 are opened. To the limit.

  In step S13, the control device 14 determines whether or not fluid is ejected from the nozzle hole 112 when the actuator is operated in step S124. Specifically, it is detected whether or not the fluid has been ejected by the flow meter 7 provided in the middle of the circulation pipe 12.

  When a signal indicating that the fluid is flowing through the circulation pipe 12 is input from the flow meter 7 to the control device 14, the control device 14 determines that the fluid circuit of the injector 100 is filled with the fluid, and the process is illustrated in FIG. The step moves to the running operation process of step S2. On the other hand, if a signal indicating that the fluid is flowing through the circulation pipe 12 is not input from the flow meter 7 to the control device 14, the control device 14 indicates that there is a portion where the fluid is not filled in the fluid circuit of the injector 100. Judgment is made, the process is returned to step S11, and the negative pressure process is performed again. The controller 14 repeats the negative pressure process and the high pressure fluid supply process until the signal is input from the flow meter 7 in step S13.

  Here, it is determined whether or not the fluid has been injected from the nozzle hole 112 that the fluid circuit is filled with the fluid. Thereby, even if it is an injector of the type like the injector 100, completion of the fluid filling can be appropriately determined. In other words, it is possible to appropriately determine the timing for shifting from the performance inspection start process in step S1 to the running operation process in step S2.

  As shown in FIGS. 6 and 7, the injector 100 has a complicated fluid circuit or a sliding gap in the fluid circuit. For this reason, it is difficult to completely fill the fluid in the fluid circuit by the high-pressure fluid supply process in step S12 once. A small amount of gas remains in the fluid circuit. According to this method, since the negative pressure process (step S11) and the high pressure fluid supply process (step S12) are alternately performed, the gas remaining in the fluid circuit can be removed in a short time. The fluid can be filled to every corner of the fluid circuit.

1 is an overall configuration diagram of an injector performance inspection apparatus according to the present invention. It is a flowchart which shows the flow of the performance test | inspection of an injector. It is a flowchart which shows the flow of the performance inspection start process in FIG. It is a flowchart which shows the flow of the negative pressure process in FIG. It is a flowchart which shows the flow of the high pressure fluid supply process in FIG. It is sectional drawing of the injector which shows the state at the time of an injection stop. It is sectional drawing of the injector which shows the state at the time of injection.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Injector performance inspection apparatus, 2 Work holding part, 3 Supply side high pressure fluid supply part (1st high pressure fluid supply means), 4 Discharge side high pressure fluid supply part (2nd high pressure fluid supply means), 5 Negative pressure part (Negative pressure) Generating means), 6 pressure holding unit, 7 flow meter (fluid sensing means), 8 first supply pipe (first pipe), 9 second supply pipe (second pipe), 10 negative pressure supply pipe (third pipe) , 11 Return piping, 12 Recirculation piping (4th piping), 13 Tank, 14 Control device, 31 1st supply pump, 32 1st high pressure control valve, 41 2nd supply pump, 42 2nd high pressure control valve (switching means) , 51 Air supply pump, 52 Pump control valve, 53 Ejector, 54 Negative pressure control valve (switching means), 61 Check valve, 62 Pressure control valve, 100 Injector, 101 Nozzle, 102 Back pressure Control body, 110 body, 111 first vertical hole, 112 injection hole, 113 seat, 114 second vertical hole, 120 nozzle needle, 121 large diameter part, 122 small diameter part, 130 valve needle (actuator), 131 small diameter piston (actuator) ), 132 Valve body (actuator), 133 Sliding piston (actuator), 140 Large-diameter piston (actuator), 150 Piezo stack (actuator), 161 First spring, 162 Second spring, 163 Third spring, 164 Fourth Spring, 170 Oil reservoir (fluid circuit), 171 Back pressure chamber (fluid circuit), 172 Valve chamber (fluid circuit), 173 Return port, 174 High pressure port, 175 Spring chamber (fluid circuit), 176 Hydraulic chamber (fluid) Circuit), 177 Small diameter piss Chamber (fluid circuit), 178 stack chamber (fluid circuit), 179 sliding piston chamber (fluid circuit), 180 high pressure passage (fluid circuit), 181 high pressure passage port (supply passage port), 182 high pressure communication passage (fluid circuit) ), 190 Return passage (fluid circuit), 191 Return passage port (discharge passage port), 192 Return communication passage (fluid circuit)

Claims (14)

A fluid circuit having a supply passage port at one end and a discharge passage port at the other end, a nozzle hole provided in the middle of the fluid circuit, a nozzle needle housed in the fluid circuit, and opening and closing the nozzle hole; An injector for inspecting performance of an injector for filling a fluid into an injector comprising: an actuator for changing a fluid flow path or fluid pressure in the fluid circuit so as to open and close a nozzle needle,
A first high-pressure fluid supply step for supplying a high-pressure fluid into the fluid circuit from the supply passage port;
A second high-pressure fluid supply step for supplying a high-pressure fluid into the fluid circuit from the discharge passage port;
A method for starting performance inspection of an injector, comprising:   2. The injector performance inspection start method according to claim 1, wherein the first high-pressure fluid supply step and the second high-pressure fluid supply step are performed substantially simultaneously. Comprising a negative pressure step of bringing the fluid circuit into a negative pressure state;
3. The injector performance inspection start method according to claim 1, wherein the negative pressure step is performed before the first high-pressure fluid supply step and the second high-pressure fluid supply step.   4. The injector performance inspection start method according to claim 3, wherein the negative pressure step, the first high pressure fluid supply step, and the second high pressure fluid supply step are alternately repeated.   The injector according to any one of claims 1 to 4, further comprising an actuator operation step for operating the actuator so as to change a fluid flow path or a fluid pressure in the fluid circuit. How to start performance inspection.   6. The injector performance inspection start method according to claim 5, wherein the actuator operation step is performed during the first high-pressure fluid supply step or the second high-pressure fluid supply step. When performing the actuator operation step,
The injector performance inspection start method according to claim 5 or 6, wherein when the fluid is ejected from the nozzle hole, it is determined that the fluid has been filled into the injector. A fluid circuit having a supply passage port at one end and a discharge passage port at the other end, a nozzle hole provided in the middle of the fluid circuit, a nozzle needle housed in the fluid circuit, and opening and closing the nozzle hole; An injector for inspecting performance of an injector for filling a fluid into an injector comprising an actuator for changing a fluid flow path or fluid pressure in the fluid circuit so as to open and close a nozzle needle,
First high-pressure fluid supply means for supplying a high-pressure fluid connected to the supply passage port via a first pipe to the fluid circuit;
Second high-pressure fluid supply means for supplying a high-pressure fluid connected to the discharge passage port via a second pipe to the fluid circuit;
A controller for operating the first high-pressure fluid supply means and the second high-pressure fluid supply means to supply the high-pressure fluid to the fluid circuit;
A device for inspecting performance of an injector, comprising:   9. The injector performance according to claim 8, wherein the control device operates the first high-pressure fluid supply unit and the second high-pressure fluid supply unit substantially simultaneously to supply the high-pressure fluid to the fluid circuit. Inspection start device. The second pipe has a third pipe branched from the pipe, and the third pipe is connected to negative pressure generating means for making the inside of the fluid circuit into a negative pressure state.
In the middle of the second pipe or the third pipe, the first connection state in which the discharge passage port and the second high-pressure fluid supply means are connected, or the discharge passage port and the negative pressure generating means are connected. Switching means for switching the second connection state is provided,
9. The control device according to claim 8, wherein the control unit switches the switching unit to the second connection state before setting the switching unit to the first connection state, and operates the unit selected for connection. The injector performance inspection start device according to claim 9.   The control device causes the switching means to alternately and repeatedly switch between the first connection state and the second connection state, and one of the negative pressure generating means and the second high-pressure fluid supply means that is selected for connection. 11. The injector performance inspection start device according to claim 10, wherein the injector is operated.   The control device operates the first high-pressure fluid supply unit and the second high-pressure fluid supply unit and operates the actuator so as to change a fluid flow path or a fluid pressure in the fluid circuit. The injector performance inspection starting device according to any one of claims 8 to 11.   13. The injector performance inspection start device according to claim 12, wherein the control device operates the actuator while operating the second high-pressure fluid supply unit. A fourth pipe that receives fluid ejected from the nozzle hole is connected to the nozzle hole,
The fourth pipe is provided with fluid sensing means for sensing fluid flowing in the pipe,
14. The control device according to claim 8, wherein the control device determines that filling of the fluid into the injector is completed when receiving a signal indicating that the fluid is sensed from the fluid sensing means. The injector performance inspection start device according to the item.

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