JP2013217202A - Oil jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil jet configured to automatically and mechanically adjust valve opening pressure, according to oil temperatures.SOLUTION: A body 2 of an oil jet 100 includes: an oil supply port 6 opened to an oil passage 72 of a cylinder block 70; a cylinder 4; and an oil injection port 10; and an oil discharge port 12. A cylinder 4 houses a piston valve 20 and a sleeve valve 30. The piston valve 20 includes a differential pressure chamber 8 as a closed section formed in the cylinder 4. The sleeve valve 30 is housed in the pressure difference chamber 8. An orifice 22 is formed in the piston valve 20 to connect the differential pressure chamber 8 to an oil supply port 6. A first spring 14 biases the piston valve 20 to a position for closing the oil injection port 10. A second spring 16 biases the sleeve valve 30 to a position for closing the oil discharge port 12. The body 2 has a leak port 52 formed to leak oil from the differential pressure chamber 8 to the outside of the body 2.

Description

  The present invention relates to an oil jet used for cooling a piston of an internal combustion engine.

  An oil passage through which pressurized oil flows is formed in the cylinder block of the internal combustion engine. The oil jet is a device that injects oil supplied from the oil passage between the piston and the piston and the cylinder bore, and thereby cools the piston that has become hot. Conventionally used oil jets have a mechanism for opening and closing a valve in accordance with hydraulic pressure. Specifically, the valve body is biased by a spring in a direction against the hydraulic pressure, and when the force received by the hydraulic pressure exceeds the force of the spring, the valve body separates from the valve seat and the valve opens. It is like that. While the hydraulic pressure increases as the rotational speed of the internal combustion engine increases, the piston temperature increases as the rotational speed increases. Therefore, according to the above mechanism, oil is injected to cool the piston while the piston is hot. In a situation where the temperature of the piston is not high, overcooling can be prevented by stopping oil injection.

  The oil jet described in Patent Document 1 below also includes a spring mechanism for opening and closing a valve in accordance with hydraulic pressure. The oil jet further has a mechanism for changing the oil injection amount in accordance with the oil temperature. The mechanism is a throttle member disposed upstream of the valve. A plurality of aperture holes are formed in the aperture member. When passing through these throttle holes, the oil is subjected to flow resistance, and its magnitude increases as the viscosity of the oil increases. For this reason, when the temperature of the oil is low and the viscosity of the oil is high, the flow rate of the oil passing through the throttle hole decreases. When the temperature of the oil is high and the viscosity of the oil is low, the flow rate of oil passing through the throttle hole increases. With such a mechanism, when the valve is opened due to an increase in hydraulic pressure, the oil injection amount is suppressed because the oil temperature is low if it is cold immediately after the engine is started, and if the oil is warmed up, As the temperature rises, the oil injection amount is increased.

JP 2011-064155 A

  The oil jet described in Patent Document 1 is configured so that its operating state changes not only by oil pressure but also by oil temperature. Since the oil temperature is closely related to the temperature state of the piston as well as the oil pressure, the configuration in which the operating state of the oil jet is switched according to the oil temperature is a general oil that simply opens and closes the valve according to the oil pressure. It is considered that the piston can be cooled more appropriately by the injection of oil than the jet.

  However, there is a problem with the oil jet described in Patent Document 1. In the oil jet described in Patent Document 1, since a throttle member is disposed in the oil flow path, pressure loss occurs when the oil passes through the throttle member. If the oil temperature is high and the viscosity of the oil is low, the generated pressure loss is small, but the pressure loss is large compared to an oil jet without a throttle member. Accordingly, the amount of oil injected to the piston at a high temperature decreases. Furthermore, even if the oil pressure rises, the oil injection amount is suppressed until the oil temperature becomes sufficiently high, so that when the cold internal combustion engine is operated at a high speed, the piston becomes hot. In spite of this, a sufficient amount of oil may not be injected.

  The problems described above can be solved by changing the valve opening pressure when the valve opens according to the oil temperature. That is, if the valve opening pressure can be increased when the oil temperature is low and the valve opening pressure can be decreased as the oil temperature increases, the problem that occurs in each oil jet described in Patent Document 1 does not occur. However, the means is preferably a mechanical oil jet. In the case of an oil jet that opens and closes a valve by a solenoid, the opening and closing of the valve can be electrically operated in accordance with the hydraulic pressure and the oil temperature. However, considering the reliability and cost, a mechanical oil jet is more advantageous.

  This invention is made | formed in view of such a subject, and it aims at providing the oil jet by which valve opening pressure is automatically adjusted automatically according to oil temperature.

  The oil jet according to the present invention includes at least a body, a piston valve, a sleeve valve, a first spring, and a second spring. The body is an oil jet main body attached to a cylinder block of the internal combustion engine, and has an oil supply port, a cylinder, an oil injection port, and an oil discharge port. The oil supply port is formed so as to open to an oil passage in the cylinder block when the body is attached to the cylinder block. One end of the cylinder communicates with the oil supply port and the other end is closed. The oil injection port opens to the side surface of the cylinder, and the oil discharge port opens to the bottom side of the cylinder from the oil injection port on the side surface of the cylinder. The piston valve is accommodated in the cylinder to form a closed compartment in the cylinder, and the sleeve valve is accommodated in the closed compartment and is slidable along the side surface of the cylinder. The piston valve is formed with an orifice that allows the closed section to communicate with the oil supply port. The first spring is disposed between the piston valve and the sleeve valve and urges the piston valve to a position where the oil injection port is closed. The second spring is disposed between the sleeve valve and the bottom surface of the cylinder and biases the sleeve valve to a position where the oil discharge port is closed. Furthermore, in the oil jet according to the present invention, the body is formed with a leak hole through which oil leaks from the closed section in the cylinder to the outside of the body. In addition, the first spring and the second spring are configured such that when the piston valve moves to the bottom side of the cylinder, the oil injection port is unblocked by the piston valve and the oil injection port communicates with the oil supply port. First, the spring length and the spring constant are adjusted so that the oil discharge port is unblocked by the sleeve valve and the oil discharge port and the closed section communicate with each other.

  According to the above configuration of the oil jet according to the present invention, the oil injection port is opened and closed by the piston valve. On the piston valve, the pressure of the oil flowing through the oil passage in the cylinder block acts, and at the same time, the pressure of the oil in the closed compartment and the urging force of the first spring act in the opposite direction. When the force received by the piston valve from the oil pressure in the oil passage is greater than the resultant force of the force received by the piston valve from the oil pressure in the closed compartment and the biasing force by the first spring, the piston valve is removed from the oil passage. It moves from the position where it is pushed by the supplied oil and closes the oil injection port. As a result, the piston valve is opened, the oil injection port and the oil supply port communicate with each other, and oil is supplied to the oil injection port to achieve oil injection.

  The oil pressure in the closed compartment changes depending on the relationship between the flow rate of oil flowing into the closed compartment through the orifice and the flow rate of oil leaking from the closed compartment through the leak hole. In the oil jet according to the present invention, the orifice and the leak hole are different in factors that determine the flow rate. For orifices where the relationship between flow and pressure follows Bernoulli's theorem, the oil density affects the flow. More specifically, the flow rate of the oil that passes through the orifice and flows into the closed section from the oil injection port side is inversely proportional to the 1/2 power of the oil density. On the other hand, in a leak hole whose flow rate is determined by Hagen-Poiseuille's law, the oil viscosity affects the flow rate. More specifically, the flow rate of oil that passes through the leak hole and leaks from the closed section of the cylinder to the outside of the body is inversely proportional to the oil viscosity. What is important here is that the sensitivity to oil temperature differs greatly between oil density and oil viscosity. There is almost no change in the oil density with respect to the change in the oil temperature, and the oil density can be regarded as almost constant in the normal temperature range of the oil in the internal combustion engine. On the other hand, the change in oil viscosity with respect to the change in oil temperature is extremely large. Although depending on the type of oil, the oil viscosity during cold is 10 times or more higher than the oil viscosity after warm-up. For this reason, when compared with the pressure in the same closed compartment, the flow rate of oil flowing from the orifice into the closed compartment does not vary greatly depending on the oil temperature, but the flow rate of oil leaking from the leak hole increases as the oil temperature increases. To do. The greater the flow rate of oil leaking from the leak hole, the greater the drop in hydraulic pressure in the closed compartment.

  Since the urging force of the spring is constant, the hydraulic pressure in the oil passage, that is, the valve opening pressure necessary to move the piston valve is determined by the hydraulic pressure in the closed compartment. When the oil temperature is high, such as after the warm-up is completed, the oil viscosity is low, so that oil easily leaks from the closed compartment, and as a result, the valve opening pressure becomes low because the pressure in the closed compartment becomes low. . On the other hand, when the oil temperature is low, such as when it is cold, the oil viscosity is high so that oil does not leak easily from the closed compartment, and as a result, the pressure in the closed compartment increases and the valve opening pressure also increases. . That is, according to the configuration of the oil jet according to the present invention, the valve opening pressure is mechanically automatically adjusted so that the valve opening pressure is lower as the oil temperature is higher and the valve opening pressure is higher as the oil temperature is lower. The

  Note that various shapes can be adopted as the shape of the leak hole. When the oil jet has a columnar stopper that is inserted into the closed compartment from the bottom of the cylinder and passes through the sleeve valve to limit the movement range of the piston valve, a hole and stopper for passing the stopper formed in the body The leak hole can be formed by a gap formed between the side surfaces of the two. The shape of the leak hole in that case can be an annular gap surrounding the stopper. In addition, long pores that lead from the top surface or side surface of the stopper to the outer surface of the body can be formed as leak holes. Furthermore, long pores and slits that lead from the bottom surface or side surface of the cylinder to the outer surface of the body can be formed as leak holes.

  By the way, when the oil temperature is low and the oil viscosity is high, the hydraulic pressure in the closed compartment may increase as the piston valve starts to move toward the bottom of the cylinder. Since the flow rate of oil leaking from the leak hole is inversely proportional to the oil viscosity, if the oil viscosity is high, the amount of oil leaking from the leak hole cannot catch up with the movement of the piston valve, and the oil in the closed compartment is compressed by the piston valve Because. The increase in the hydraulic pressure in the closed compartment slows down the movement of the piston valve and hinders the communication between the oil supply port and the oil injection port.

  However, according to the above configuration of the oil jet according to the present invention, when the piston valve is pushed and moved to the bottom side of the cylinder by the oil pressure in the oil passage, the oil injection port is blocked by the piston valve. First, the oil discharge port is unblocked by the sleeve valve, and the oil discharge port communicates with the closed compartment. The oil in the closed section is discharged from the oil discharge port by the communication between the oil discharge port and the closed section, whereby the hydraulic pressure in the closed section is greatly reduced, and the piston valve moves to a position where the oil injection port is opened. . As a result, the piston valve is reliably opened and the oil injection port and the oil supply port communicate with each other, and oil is supplied to the oil injection port to achieve oil injection.

  In the oil jet according to the present invention, the oil discharged from the oil discharge port may be used for cooling the piston. By attaching an oil injection nozzle connected to the oil injection port to the body, the discharged oil can be used for cooling the piston. Since the oil discharge port opens before the oil injection port, the piston is cooled using the oil discharged from the oil discharge port until the piston valve descends and the oil injection port opens. be able to. This is particularly effective at low oil temperatures where it takes time for the oil injection port to open due to increased pressure in the closed compartment.

  As described above, according to the oil jet of the present invention, the valve opening pressure can be mechanically automatically adjusted according to the oil temperature. In addition, even when the oil temperature is high and the oil temperature is low, the piston valve can be reliably opened to achieve oil injection.

It is a longitudinal cross-sectional view which shows typically the structure of the oil jet which concerns on Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. It is a figure for demonstrating operation | movement of the oil jet which concerns on Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the oil jet which concerns on Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the oil jet which concerns on Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the oil jet which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows typically the structure of the oil jet which concerns on Embodiment 2 of this invention. It is the BB sectional view taken on the line of FIG. It is a figure corresponding to the BB sectional view of Drawing 7 showing the modification of the number of leak holes. It is a figure corresponding to the BB sectional view of Drawing 7 showing the modification of the shape of a leak hole. It is a figure corresponding to FIG. 7 which shows the modification of the position which forms a leak hole. It is a figure corresponding to FIG. 7 which shows the modification of the position which forms a leak hole.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.

  The configuration of the oil jet according to Embodiment 1 of the present invention can be described with reference to FIGS. 1 and 2. As schematically shown in the longitudinal sectional view of FIG. 1, an oil jet 100 according to the present embodiment includes a body 2 attached to a cylinder block 70 of an internal combustion engine. The cylinder block 70 is formed with an oil passage 72 through which oil pressurized by an oil pump flows. Since the oil pump is driven by the power received from the crankshaft of the internal combustion engine, the hydraulic pressure in the oil passage 72 is low when the rotational speed of the internal combustion engine is low, and the hydraulic pressure in the oil passage 72 increases as the rotational speed increases. Go. An oil supply port 6 that opens to the oil passage 72 is formed in the body 2.

  The body 2 is formed with a cylinder 4 having an oil supply port 6 as an inlet. The cylinder 4 is formed through the body 2, and its outlet is covered with a holder 50 described later. Thus, a space is formed in the cylinder 4 where one end is open and the other end is closed. An oil injection port 10 having a smaller diameter than the cylinder 4 is open near the inlet on the side surface of the cylinder 4. Furthermore, an oil discharge port 12 having substantially the same diameter as the oil injection port 10 is opened on the side of the cylinder 4 on the bottom side of the cylinder 4 with respect to the oil injection port 10. Two oil injection nozzles 60 and 64 are attached to the body 2 by brazing or the like. Of these, an oil injection passage 62 formed in the first oil injection nozzle 60 communicates with the oil injection port 10. The oil injection passage 66 formed in the second oil injection nozzle 64 is communicated with the oil discharge port 12. The tips of these oil injection nozzles 60 and 64 are directed to the back surface of the piston of the internal combustion engine or between the piston and the cylinder bore.

  In the cylinder 4, a piston valve 20, a first spring 14, a sleeve valve 30, and a second spring 16 are accommodated in order from the inlet side (the oil supply port 6 side). A valve seat 18 of the piston valve 20 is formed at the inlet of the cylinder 4. The oil injection port 10 is formed at a position where the piston valve 20 is closed by the piston valve 20 when the piston valve 20 is seated on the valve seat 18. Both the first spring 14 and the second spring 16 are coiled compression springs. These springs 14 and 16 position the piston valve 20 on the valve seat 18 and at the same time position the sleeve valve 30 at the position closing the oil discharge port 12. A communication hole 34 that communicates from the inside to the outside of the sleeve valve 30 is formed on the side of the sleeve valve 30 that faces the oil discharge port 12. The spring length of each of the springs 14 and 16 is such that the communication hole 34 of the sleeve valve 30 is slightly displaced from the oil discharge port 12 toward the oil injection port 10 in a state where the piston valve 20 is seated. The communication hole 34 of the sleeve valve 30 and the oil discharge port 12 are adjusted so as not to communicate with each other. The spring lengths and spring constants of the springs 14 and 16 are set before the oil injection port 10 is unblocked by the piston valve 20 when the piston valve 20 is pushed and moved toward the bottom of the cylinder 4. The oil discharge port 12 and the differential pressure chamber 8 are adjusted to communicate with each other through the communication hole 34.

  Further, a stopper 42 for limiting the movement range of the piston valve 20 is provided in the cylinder 4. The stopper 42 has a cylindrical shape, protrudes from the bottom of the cylinder 4 into the cylinder 4 and penetrates the central hole 32 of the sleeve valve 30. The bottom of the cylinder 4 is formed by a holder 50 embedded in the body 2. A plug 40 with an integrated stopper 42 is fitted into the holder 50, and the stopper 42 is inserted into the cylinder 4 through a hole formed in the holder 50. The holder 50 and the plug 40 are separate pieces from the body 2, but can be regarded as a part of the body 2.

  A closed section 8 surrounded by the piston valve 20 and the side surface and bottom of the cylinder 4 is formed in the cylinder 4. The sleeve valve 30 slides along the side surface of the cylinder 4 in the closed section 8. The piston valve 20 is formed with an orifice 22 that allows the closed section 8 to communicate with the oil supply port 6 side. For this reason, when the oil jet 100 is attached to the cylinder block 70, the closed section 8 is filled with oil through the orifice 22. However, a differential pressure with respect to the hydraulic pressure of the oil passage 62 is generated in the hydraulic pressure of the closed section 8 by the configuration described below. Hereinafter, the closed section 8 is referred to as a differential pressure chamber. Since the central hole 32 of the sleeve valve 30 is larger in each stage than the orifice 22, no differential pressure is generated before and after that.

  The bottom of the differential pressure chamber 8 is formed by a holder 50, and the holder 50 has a hole for inserting the stopper 42 into the differential pressure chamber 8. A slight gap 52 is formed between the hole and the peripheral surface of the stopper 42. More specifically, as shown in FIG. 2, an annular gap 52 surrounding the periphery of the stopper 42 is formed. The annular gap 52 is provided to allow oil in the differential pressure chamber 8 to leak out of the body 2, and the cross-sectional area of the flow path is markedly greater than the cross-sectional area of the differential pressure chamber 8. It is formed small. Hereinafter, this annular gap is referred to as a leak hole 52. By forming such a leak hole 52 in the body 2, oil leaks out of the body 2 from the differential pressure chamber 8, thereby reducing the hydraulic pressure in the differential pressure chamber 8. That is, a differential pressure is generated between the hydraulic pressure in the oil passage 72 and the hydraulic pressure in the differential pressure chamber 8.

  Between the holder 50 and the plug 40, an oil discharge chamber 54 for discharging oil leaking from the leak hole 52 to the outside is formed. The oil discharge chamber 54 communicates with the outside of the body 2 through a plurality of oil discharge holes 44 formed in the plug 40. The total channel cross-sectional area of the oil discharge hole 44 is much larger than the channel cross-sectional area of the leak hole 52. Therefore, the oil leaked from the leak hole 52 to the oil discharge chamber 54 is quickly discharged out of the body 2 through the oil discharge hole 44 without filling the oil discharge chamber 54 and the oil discharge hole 44.

  Next, the operation of the oil jet 100 according to the present embodiment will be described with reference to FIGS. In these drawings, the oil flow in each state is indicated by an arrow line.

  According to the configuration of the oil jet 100 according to the present embodiment, the oil pressure of the oil flowing through the oil passage 72 acts on the piston valve 20 from the oil supply port 6 side. At the same time, the hydraulic pressure in the differential pressure chamber 8 and the urging force of the first spring 14 act on the piston valve 20 from opposite directions. The former acts as a force in the valve opening direction on the piston valve 20, and the latter acts as a force in the valve closing direction. Therefore, if the resultant force of the hydraulic pressure in the differential pressure chamber 8 and the biasing force of the first spring 14 is greater than or equal to the hydraulic pressure in the oil passage 72, as shown in the schematic diagram of FIG. 20 is held at a position where the oil injection port 10 is closed while seated. That is, the piston valve 20 is maintained in a closed state. Further, since the piston valve 20 does not move, the sleeve valve 30 does not move and remains held at a position where the oil discharge port 12 is closed.

  When the force due to the hydraulic pressure in the oil passage 72 is greater than the resultant force of the hydraulic pressure in the differential pressure chamber 8 and the urging force of the first spring 14, as shown in the schematic diagram of FIG. 20 is pushed by the oil supplied from the oil passage 72 and leaves the valve seat 18. That is, the piston valve 20 starts to open.

The hydraulic pressure in the oil passage 72 at this time, that is, the valve opening pressure is determined by the hydraulic pressure in the differential pressure chamber 8. The hydraulic pressure in the differential pressure chamber 8 varies depending on the relationship between the flow rate of oil entering the differential pressure chamber 8 and the flow rate of oil exiting the differential pressure chamber 8. Since oil flows into the differential pressure chamber 8 through the orifice 22, the flow rate Q 1 is in accordance with Bernoulli's theorem as expressed by the following formula 1. That is, the flow rate Q1 of the oil passing through the orifice 22 is proportional to the square of the differential pressure between the hydraulic pressure P _{M / G} in the oil passage 72 and the hydraulic pressure P _IN in the differential pressure chamber 8, and the oil density ρ is 1. / Inversely proportional to the square. In Equation 1, C is a flow coefficient, and A is a flow path cross-sectional area of the orifice 22.

On the other hand, since oil leaks from the differential pressure chamber 8 through the leak hole 52, the flow rate Q2 follows the Hagen-Poiseuille's law as expressed by the following equation 2. That is, the flow rate Q2 of the oil passing through the leak hole 52 is proportional to the differential pressure between the hydraulic pressure P _IN and the atmospheric pressure P _OUT in the differential pressure chamber 8, and inversely proportional to the oil viscosity η. In Equation 2, B is a coefficient.

  As can be seen from the above two equations, the oil density affects the flow rate of oil passing through the orifice 22, but the oil viscosity affects the flow rate of oil passing through the leak hole 52. Oil density and oil viscosity are both affected by oil temperature, but their sensitivity differs greatly. That is, there is almost no change in the oil density with respect to the change in the oil temperature, and the oil density is almost constant in the temperature range from the cold time to the completion of warm-up, whereas the change in the oil viscosity with respect to the change in the oil temperature is extremely large. Although depending on the type of oil, the oil viscosity during cold is 10 times or more higher than the oil viscosity after warm-up.

  Due to the characteristics of the oil density and the oil viscosity with respect to the oil temperature, the flow rate of the oil flowing into the differential pressure chamber 8 from the orifice 22 does not vary greatly depending on the oil temperature, but the flow rate of the oil leaking from the leak hole 52 is It increases with increasing temperature. As the flow rate of oil leaking from the leak hole 52 increases, the hydraulic pressure in the differential pressure chamber 8 decreases, and the hydraulic pressure in the oil passage 72 required to open the piston valve 20, that is, the valve opening pressure decreases. Therefore, when the oil temperature is high as after the warm-up is completed, the oil is likely to leak from the leak hole 52, so that the valve opening pressure is low. When the oil temperature is low as in the cold time, the leak hole 52 Since the oil is difficult to leak from, the valve opening pressure becomes high. That is, according to the oil jet 100 according to the present embodiment, the valve opening pressure is mechanically automatically adjusted so that the higher the oil temperature is, the lower the pressure is, and the higher the oil temperature is.

  However, since the flow rate of oil leaking from the leak hole 52 is inversely proportional to the oil viscosity, when the oil temperature is low and the oil viscosity is high, the amount of oil leaked from the leak hole 52 cannot catch up with the movement of the piston valve 20 There is. In this case, since the oil in the differential pressure chamber 8 is compressed by the piston valve 20, the hydraulic pressure in the differential pressure chamber 8 increases as the piston valve 20 starts to move to the bottom side of the cylinder 4. The increase in the hydraulic pressure in the differential pressure chamber 8 slows the movement of the piston valve 20 in the direction to open the oil supply port 10.

  However, when the piston valve 20 moves while being pushed to the bottom side of the cylinder 4, as shown in the schematic diagram of FIG. 5, the sleeve is moved before the oil injection port 10 is opened by the lowering of the piston valve 20. The oil discharge port 12 and the differential pressure chamber 8 communicate with each other through the communication hole 34 of the valve 30. Accordingly, the oil in the differential pressure chamber 8 is discharged from the oil discharge port 12 before the oil is supplied from the oil supply port 6 to the oil injection port 10. The oil discharged from the oil discharge port 12 is injected from the second oil injection nozzle 64 toward the piston. Thus, the piston can be cooled using the oil discharged from the oil discharge port 12 until the piston valve 20 is sufficiently lowered and the oil injection port 10 is opened.

  Then, as the oil is continuously discharged from the oil discharge port 12, the hydraulic pressure in the differential pressure chamber 8 is greatly reduced. As the hydraulic pressure in the differential pressure chamber 8 decreases, the piston valve 20 is pushed down by the hydraulic pressure in the oil passage 72. As a result, as shown in the schematic diagram of FIG. 6, the oil injection port 10 is unblocked by the piston valve 20 and the oil injection port 10 and the oil supply port 6 communicate with each other. As a result, oil is supplied to the oil injection port 10 and oil injection from the first oil injection nozzle 60 is started.

  As described above, according to the oil jet 100 according to the present embodiment, the valve opening pressure can be mechanically automatically adjusted according to the oil temperature. Further, when the oil temperature is such that the piston valve 20 is not easily lowered, the sleeve valve 30 is opened first, and the hydraulic pressure in the differential pressure chamber 8 is lowered, so that the piston valve 20 is reliably opened and the first oil injection nozzle is opened. Oil injection from 60 can be achieved. Further, since the oil extracted from the oil discharge port 12 to lower the hydraulic pressure in the differential pressure chamber 8 is used for cooling the piston, the piston temperature before full-scale oil injection from the first oil injection nozzle 60 starts. Can be prevented from rising.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to the drawings.

  The configuration of the oil jet 200 according to Embodiment 2 of the present invention can be described with reference to FIGS. 7 and 8, elements having the same configuration or function as those of the oil jet 100 according to Embodiment 1 shown in FIG. The difference between the oil jet 200 according to the present embodiment and the oil jet 100 according to the first embodiment is the shape of a leak hole that leaks oil from the differential pressure chamber 8 to the outside of the body 2. In the oil jet 200 according to the present embodiment, as shown in FIG. 7 and FIG. 8, long pores that lead from the bottom surface of the cylinder 4 to the outer surface of the body 2 are formed, and these function as the leak holes 90. ing. The flow passage cross-sectional area of the leak hole 90 is significantly smaller than the cross-sectional area of the differential pressure chamber 8. The flow rate of the oil leaking from the leak hole 90 formed in this way is inversely proportional to the oil viscosity as expressed by the above-described equation 2. In the oil jet 200 according to the present embodiment, a plug 80 integrated with a stopper 82 is fitted into the outlet of the cylinder 4 formed in the body 2, and the bottom of the cylinder 4 is formed by the plug 80.

  The flow rate of the oil leaking from the leak hole 90 which is a long pore is small when the oil temperature is low and increases when the oil temperature is high. For this reason, the lower the oil temperature, the higher the oil pressure in the differential pressure chamber 8 and the higher the valve opening pressure, and the higher the oil temperature, the lower the oil pressure in the differential pressure chamber 8 and the lower the valve opening pressure. That is, according to the oil jet 200 according to the present embodiment, the valve opening pressure is mechanically and automatically adjusted according to the oil temperature, as in the first embodiment.

Others.
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following modifications can be made.

  In the second embodiment, the number of leak holes 90 that are long pores is not limited to one. For example, two leak holes 90 may be formed as shown in FIG. 9, or a larger number of leak holes 90 may be formed. The number of the leak holes 90 may be determined so that a desired valve opening pressure-oil temperature characteristic can be obtained based on the cross-sectional area of the orifice 22 and the volume of the differential pressure chamber 8.

  The shape of the leak hole in the second embodiment can be changed from a long hole to a slit. That is, the slit as shown in FIG. Even in the case of such a slit-like leak hole 94, the flow rate of oil leaking from the leak hole 94 can be appropriately adjusted by appropriately setting the slit length and width. In addition, a plurality of slit-like leak holes 94 can be formed in the same manner as the long pore-like leak holes.

  Furthermore, the position of the leak hole in the second embodiment can be moved from the bottom surface of the cylinder 4 to another position. For example, like an oil jet 300 shown in FIG. 11, a leak hole 94 that leads from the top surface of the stopper 82 to the outer surface of the body 2 can be formed. In this case, the shape of the leak hole 94 is preferably a long hole. Further, as in the oil jet 400 shown in FIG. 12, a leak hole 96 that communicates from the side surface of the cylinder 4 to the outer surface of the body 2 can be formed. In this case, the shape of the leak hole 96 may be a long hole or a slit.

  The communication hole 34 provided in the sleeve valve 30 may be eliminated. Even in such a case, by appropriately adjusting the initial position of the sleeve valve 30 with respect to the oil discharge port 12, it is possible to first release the blockage of the oil discharge port 12 by the sleeve valve 30 at a low oil temperature at which the piston valve 20 is difficult to descend. it can.

2 Body 4 Cylinder 6 Oil supply port 8 Differential pressure chamber 10 Oil injection port 12 Oil discharge port 14 First spring 16 Second spring 18 Valve seat 20 Piston valve 22 Orifice 30 Sleeve valve 34 Communication hole 40 Plug 42 Stopper 44 Oil discharge hole 50 Holder 52 Leak hole (annular gap)
54 Oil discharge chamber 60 First oil injection nozzle 64 Second oil injection nozzle 70 Cylinder block 72 Oil passage 80 Plug 82 Stopper 90, 94, 96 Leak hole (long pore)
92 Leak hole (slit)
100, 200, 300, 400 Oil jet

Claims (4)

An oil supply port that opens to an oil passage in a cylinder block of an internal combustion engine, a cylinder that has one end communicating with the oil supply port and the other end that is closed, and an oil injection port that opens to the side of the cylinder And a body having an oil discharge port that opens to the bottom side of the cylinder relative to the oil injection port on the side surface of the cylinder;
A piston valve that is housed in the cylinder to form a closed section in the cylinder, and that includes an orifice that communicates the closed section with the oil supply port;
A sleeve valve accommodated in the closed compartment and slidable along a side surface of the cylinder;
A first spring disposed between the piston valve and a sleeve valve to urge the piston valve to a position closing the oil injection port;
A second spring that is disposed between the sleeve valve and the bottom surface of the cylinder and biases the sleeve valve at a position closing the oil discharge port;
The body is formed with a leak hole for oil to leak out of the body from the closed compartment,
When the piston valve moves to the bottom side of the cylinder, the first spring and the second spring are released from the oil injection port and the oil supply port when the oil injection port is unblocked by the piston valve. The spring length and the spring constant are adjusted so that the oil discharge port is unblocked by the sleeve valve and the oil discharge port and the closed section communicate with each other before the communication. Oil jet. A first oil injection nozzle attached to the body and connected to the oil injection port;
The oil jet according to claim 1, further comprising a second oil injection nozzle attached to the body and connected to the oil discharge port. A columnar stopper that is inserted into the closed compartment from the bottom of the cylinder and penetrates the sleeve valve to limit the movement range of the piston valve;
The oil jet according to claim 1 or 2, wherein the leak hole is a gap formed between a hole formed in the body for passing the stopper and a side surface of the stopper.   The oil jet according to claim 3, wherein the gap is an annular gap surrounding the periphery of the stopper.

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