JP2013144943A - Piston cooling jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piston cooling jet that can control an oil jet in a cold state.SOLUTION: The piston cooling jet 1 includes: a body 2 having a body side channel 20; a nozzle 3 having a nozzle side channel 30; a valve body 4 which allows the body side channel 20 and the nozzle side channel 30 to communicate with each other and to be interrupted from each other; and a biasing member 5 which biases the valve body 4. The biasing member 5 includes a plurality of spring parts 50, 51 having different spring constants. The valve body 4 is driven by a biasing force of the biasing member 5 and a pushing force of a hydraulic pressure of oil O. The piston cooling jet 1 can be switched among: a valve opening state in which the body side channel 20 and the nozzle side channel 30 are allowed to communicate with each other; a first valve closing state in which the valve body 4 is moved by the biasing force exceeding the pushing force with respect to the valve opening state, and the body side channel 20 and the nozzle side channel 30 are interrupted from each other; and a second valve closing state in which the valve body 4 is moved by the biasing force falling below the pushing force with respect to the valve opening state, and the body side channel 20 and the nozzle side channel 30 are interrupted from each other.

Description

  The present invention relates to a piston cooling jet that cools a piston by injecting oil onto the back of an engine piston.

  The piston cooling jet is attached to a cylinder block of the engine. The piston cooling jet communicates with the main oil gallery of the cylinder block. The main oil gallery constitutes a part of the engine oil circulation circuit. A hydraulic valve mechanism is arranged in the piston cooling jet.

  When the oil pressure of the oil in the main oil gallery exceeds a predetermined threshold value, the hydraulic valve mechanism of the piston cooling jet opens. For this reason, the oil of the main oil gallery is injected to the back surface of the piston by the piston cooling jet. The piston is cooled by the injection.

  Here, when the warm-up of the engine is completed and the piston is hot, it is preferable to cool the piston with a piston cooling jet. However, when the engine is not warmed up and the piston is at a low temperature (hereinafter referred to as “when cold”), it is necessary to raise the temperature of the piston early. For this reason, if a piston is cooled using a piston cooling jet at the time of cold, the temperature rise of a piston will be inhibited. Moreover, the oil injected to the back surface of the piston falls on the crankshaft. Here, when cold, the oil temperature is low. For this reason, the viscosity of oil is high. Therefore, oil with high viscosity falls on the crankshaft, and the rotation resistance of the crankshaft (stirring resistance against oil) increases. For these reasons, it is preferable not to inject oil when cold. However, the conventional hydraulic valve mechanism of the piston cooling jet opens and closes according to the oil pressure of the main oil gallery, not the temperature of the engine. For this reason, a piston cooling jet will operate | move even at the time of cold.

JP 2011-12619 A JP 2011-12650 A JP 2007-32416 A

  In view of this point, Patent Literatures 1 and 2 disclose a piston cooling jet including a hydraulic valve mechanism and a temperature valve mechanism. According to the piston cooling jets described in these documents, the hydraulic valve mechanism switches the oil injection state according to the oil pressure. The temperature type valve mechanism switches the oil injection state in accordance with the temperature of the oil. For this reason, when cold, the injection of oil can be stopped by closing the temperature type valve mechanism. When the piston is hot after the engine is warmed up (hereinafter referred to as “warm”) and the oil pressure is low, the temperature valve mechanism opens, but the hydraulic valve By closing the mechanism, oil injection can be stopped. In addition, when the oil pressure is high during the warm period, the temperature-type valve mechanism and the hydraulic valve mechanism can be opened to permit oil injection.

  However, a coil spring made of a Ni—Ti alloy (shape memory alloy) is used for a valve mechanism that opens and closes according to temperature. That is, a coil spring whose spring constant changes according to temperature is used. For this reason, the manufacturing cost of the valve mechanism, and hence the piston cooling jet, is increased. Further, since two valve mechanisms (hydraulic valve mechanism and temperature valve mechanism) are arranged, the structure of the piston cooling jet becomes complicated. Moreover, a piston cooling jet will enlarge.

  Patent Document 3 discloses a piston cooling jet that controls oil injection according to the engine speed. That is, the piston cooling jet described in the same document includes a hydraulic valve mechanism and an electronically controlled valve mechanism (solenoid valve). The solenoid valve is disposed on the upstream side (main oil gallery side) of the hydraulic valve. According to the piston cooling jet described in the document, oil injection can be stopped by the opening / closing control of the solenoid valve when the engine speed is high at a warm time.

  However, this document does not describe the control of oil injection during cold. In addition, since two valve mechanisms (hydraulic valve mechanism and electronically controlled valve mechanism) are arranged, the structure of the piston cooling jet is complicated. Moreover, a piston cooling jet will enlarge. In addition, the electronic control circuit configuration of the vehicle becomes complicated.

  The piston cooling jet of the present invention has been completed in view of the above problems. It is an object of the present invention to provide a piston cooling jet that can control oil injection during cold, has a simple structure, and can be downsized.

  (1) In order to solve the above-mentioned problem, a piston cooling jet according to the present invention includes a main body having a main body side channel through which oil flows, a nozzle having a nozzle side channel, the main body side channel, and the nozzle side channel. A piston cooling jet comprising a valve body capable of communicating and blocking, and a biasing member that biases the valve body, the biasing member having a plurality of spring portions having different spring constants, The valve body is driven by an urging force of the urging member and a hydraulic pressure of the oil, and a valve opening state in which the main body side channel and the nozzle side channel are communicated with each other, and the valve opening When the urging force exceeds the pressing force with respect to the state, the valve body moves, and the first valve closed state that shuts off the main body side flow path and the nozzle side flow path, and the valve open state On the other hand, when the urging force falls below the pressing force, the valve body moves, A second closed state to block the nozzle side channel, it can be switched to the features.

  The piston cooling jet of the present invention includes a main body, a nozzle, a valve body, and an urging member. The urging member has a plurality of spring portions having different spring constants. The piston cooling jet can be switched between a valve open state, a first valve closed state, and a second valve closed state.

  In the valve open state, the main body side channel and the nozzle side channel communicate with each other. In the first valve closed state, the urging force exceeds the pressing force with respect to the valve open state, so that the valve body moves. For this reason, the main body side channel and the nozzle side channel are blocked. On the contrary, in the second valve closing state, the urging force is less than the pressing force with respect to the valve opening state, so that the valve body moves. For this reason, the main body side channel and the nozzle side channel are blocked.

  Immediately after the engine starts in cold weather, the oil temperature is low. For this reason, the viscosity of the oil is high and the oil pressure of the oil is excessively high. Therefore, according to the conventional hydraulic valve mechanism of the piston cooling jet, the piston cooling jet is operated. That is, oil is injected into the piston.

  In this respect, according to the piston cooling jet of the present invention, not only the state where the hydraulic pressure is low and the biasing force of the biasing member exceeds the pressing force of the hydraulic pressure (first valve closed state), but also the hydraulic pressure is excessively high, Even in a state where the urging force is lower than the hydraulic pressure (second valve closed state), the main body side flow path and the nozzle side flow path can be shut off. For this reason, even if the oil pressure of the oil immediately after the engine is started is excessively high, the oil injection to the piston can be blocked by the second valve closing state.

  As described above, according to the piston cooling jet of the present invention, it is possible to control the injection of oil in the cold state. For this reason, the temperature of the piston can be raised quickly. Moreover, the supercooling of the piston can be suppressed. Further, the engine warm-up can be completed early. In addition, since highly viscous oil does not easily fall onto the crankshaft, it is possible to suppress an increase in the rotational resistance (stirring resistance to the oil) of the crankshaft.

  Further, according to the piston cooling jet of the present invention, it is not necessary to arrange a temperature type valve mechanism or an electronically controlled valve mechanism. For this reason, the structure is simple and downsizing is possible.

  (2) Preferably, in the configuration of (1), the valve opening state is a state where the hydraulic pressure is not less than a low pressure side threshold value and not more than a high pressure side threshold value, and the first valve closing state is the hydraulic pressure. Is less than the low-pressure side threshold value, and the second valve closing state is preferably configured such that the hydraulic pressure is in excess of the high-pressure side threshold value.

  According to this configuration, when the hydraulic pressure is not less than the low pressure side threshold value and not more than the high pressure side threshold value, the main body side channel and the nozzle side channel can be communicated with each other. That is, oil can be injected to the piston. On the other hand, when the hydraulic pressure is less than the low pressure side threshold value or exceeds the high pressure side threshold value, the main body side flow path and the nozzle side flow path can be shut off. That is, oil injection can be stopped.

  (3) Preferably, in the configuration of the above (1) or (2), the main body has a storage chamber for storing the valve body so as to be capable of reciprocating, and the valve body is the main body in the valve open state. A communication hole that communicates the side flow path and the nozzle side flow path, and is disposed on one side of the communication hole in the reciprocating direction, and shuts off the main body side flow path and the nozzle side flow path in the first valve closed state. A first blocking portion, and a second blocking portion that is disposed on the other side of the communication hole in the reciprocating direction and blocks the main body-side channel and the nozzle-side channel in the second valve closed state. Better.

  According to this structure, the 1st interruption | blocking part, the communicating hole, and the 2nd interruption | blocking part are located in a line along the reciprocating direction of a valve body. A first valve closing state can be achieved by the first blocking part, a valve opening state can be achieved by the communication hole, and a second valve closing state can be achieved by the second blocking part.

  (4) Preferably, in any one of the configurations (1) to (3), the plurality of the spring portions are arranged in series.

For example, when an external force is applied to two spring parts arranged in series (however, the number of spring parts arranged in this configuration is not limited to two), the spring constant of one spring part is k1, the deformation amount is x1, and the other If the spring constant of the spring part is k2 (> k1) and the deformation is x2, the following equation (1) is established.
x1 / x2 = k2 / k1 Formula (1)
From equation (1), it can be seen that when a plurality of spring portions are arranged in series, a spring portion having a small spring constant is more easily deformed by an external force than a spring portion having a large spring constant. According to this configuration, the valve open state, the first valve closed state, and the second valve closed state can be switched using the difference in the degree of deformation between the plurality of spring portions.

  (5) Preferably, in any one of the constitutions (1) to (4), the biasing member is disposed on the radially outer side of the first coil spring and the first coil spring. A second coil spring having a shorter axis than the first spring portion, wherein the plurality of spring portions are arranged with the first coil spring alone when viewed from the radial direction, and the first coil It is better to make it the structure which has a 2nd spring part by which a spring and this 2nd coil spring are arrange | positioned overlappingly.

The second spring portion is formed by connecting the first coil spring and the second coil spring in parallel. The first spring portion and the second spring portion are connected in series. Here, when the spring constant of the first coil spring is K1, and the spring constant of the second coil spring is K2, the spring constant Kt1 of the first spring portion is K1. On the other hand, the spring constant Kt2 of the second spring portion is derived from the following equation (2).
Kt2 = K1 + K2 Formula (2)
From equation (2), the spring constant Kt2 of the second spring part is larger than the spring constant Kt1 of the first spring part. Substituting Kt1 in equation (2) into k1 in equation (1) and Kt2 in equation (2) into k2 in equation (1), the first spring portion is more oil-filled than the second spring portion. It turns out that it is easy to deform with respect to the hydraulic pressure.

  According to this structure, a 1st valve closing state can be achieved because neither a 1st spring part nor a 2nd spring part deform | transforms. Moreover, a 2nd valve closing state can be achieved because both a 1st spring part and a 2nd spring part deform | transform. Moreover, a valve-open state can be achieved because a 1st spring part deform | transforms and a 2nd spring part does not deform | transform.

  According to the present invention, it is possible to provide a piston cooling jet that can control oil injection during cold, has a simple structure, and can be downsized.

It is a layout view of the piston cooling jet of the first embodiment. It is an enlarged view in the frame II of FIG. It is an axial sectional view in the 1st valve closing state of the piston cooling jet. It is an axial sectional view in the 2nd valve closing state of the piston cooling jet. FIG. 6 is a correlation diagram between the engine speed during cold and the oil pressure of the main oil gallery. FIG. 4 is a correlation diagram between the engine speed during warm and the oil pressure of the main oil gallery. It is an axial sectional view in the 1st valve closing state of the piston cooling jet of a second embodiment. It is an axial sectional view in the 2nd valve closing state of the piston cooling jet of a third embodiment.

  Hereinafter, embodiments of the piston cooling jet of the present invention will be described.

<First embodiment>
[Piston cooling jet arrangement]
First, the arrangement of the piston cooling jet of this embodiment will be described. FIG. 1 shows a layout diagram of the piston cooling jet of the present embodiment. As shown in FIG. 1, the engine 9 includes a cylinder block 90, a piston 91, a connecting rod 92, and a crankshaft 93. The piston 91 is connected to the crankshaft 93 via a connecting rod 92. The piston 91 can reciprocate up and down in the cylinder block 90. A main oil gallery 900 is formed in the cylinder block 90. The main oil gallery 900 constitutes a part of the oil circulation circuit of the engine 9. The piston cooling jet 1 is attached to the cylinder block 90. Note that the piston cooling jet 1 shown in FIG. 1 is in a valve open state. As shown by a thick arrow in FIG. 1, the piston cooling jet 1 can inject the oil O in the main oil gallery 900 onto the back surface (lower surface, the surface opposite to the combustion chamber) of the piston 91.

[Configuration of piston cooling jet]
Next, the structure of the piston cooling jet of this embodiment is demonstrated. FIG. 2 shows an enlarged view in the frame II of FIG. As shown in FIG. 2, the piston cooling jet 1 includes a main body 2, a nozzle 3, a valve body 4, and an urging member 5.

  The main body 2 is made of steel and has a bottomed cylindrical shape (cup shape) that opens upward. The upper end of the main body 2 is fixed to the cylinder block 90. A storage chamber 2 a is defined inside the main body 2. The storage chamber 2a is divided into an upper main body side channel 20 and a lower biasing member storage chamber 21 by a bottom wall of the valve body 4 described later. The main body side flow path 20 communicates with the main oil gallery 900 shown in FIG. A stopper portion 201 is formed at the upper end of the storage chamber 2a so as to project radially inward. Two spring seats 200a and 200b project from the bottom surface of the storage chamber 2a in a double circular shape.

  The nozzle 3 is made of steel and has a long-axis cylindrical shape. The nozzle 3 protrudes radially outward from the side peripheral wall of the main body 2. As shown in FIG. 1, the tip of the nozzle 3 faces upward, that is, in the direction of the piston 91. A nozzle-side flow path 30 is defined inside the nozzle 3. The nozzle side flow path 30 can be communicated with or blocked from the main body side flow path 20 by a valve body 4 described later.

  The valve body 4 is made of steel and has a bottomed cylindrical shape that opens upward. The valve body 4 is accommodated in the accommodation chamber 2a. The bottom wall of the valve body 4 divides the storage chamber 2a into an upper body-side flow path 20 and a lower biasing member storage chamber 21. Oil O flows in the main body side flow path 20. The biasing member accommodating chamber 21 is liquid-tightly isolated from the main body side flow path 20. The valve body 4 can reciprocate in the up-down direction within the accommodation chamber 2a. The stopper part 201 of the storage chamber 2a prevents the valve body 4 from dropping off from the storage chamber 2a. Two spring seats 40a and 40b project from the bottom surface of the bottom wall of the valve body 4 in a double circular shape. On the right side wall of the valve body 4, a second blocking part 43, a communication hole 41, and a first blocking part 42 are arranged side by side from above to below.

  The biasing member 5 includes a first coil spring 52 and a second coil spring 53. The urging member 5 is accommodated in the urging member accommodating chamber 21. The urging member 5 urges the valve body 4 upward by utilizing an extension force when returning from the contracted state to the natural length state (a state where no external force is applied). The first coil spring 52 and the second coil spring 53 are each made of steel and can be expanded and contracted in the vertical direction. The first coil spring 52 is interposed between the spring seat 40a of the valve body 4 and the spring seat 200a of the accommodation chamber 2a. The second coil spring 53 is interposed between the spring seat 40b of the valve body 4 and the spring seat 200b of the storage chamber 2a. The second coil spring 53 is disposed on the radially outer side of the first coil spring 52. The second coil spring 53 has a larger spring constant than the first coil spring 52. In the natural length state, the second coil spring 53 has a shorter axial length (length in the vertical direction) than the first coil spring 52.

[Valve open state]
Next, the valve opening state of the piston cooling jet of this embodiment will be described. As described above, the second coil spring 53 has a larger spring constant than the first coil spring 52. As shown in FIG. 2, in the valve open state, the first coil spring 52 having a small spring constant is compressed from above by the pressing force of the hydraulic pressure of the oil O. For this reason, the axial lengths of the first coil spring 52 and the second coil spring 53 are substantially the same. The upward biasing force of the first coil spring 52 and the second coil spring 53 (second spring portion 51 described later) and the downward pressing force by the oil O hydraulic pressure are balanced. In the open state, the main body side flow path 20 and the nozzle side flow path 30 communicate with each other through the communication hole 41. For this reason, the oil O flows from the main body side channel 20 into the nozzle side channel 30. That is, the oil O is injected to the piston 91 shown in FIG.

[First valve closed state]
Next, the 1st valve closing state of the piston cooling jet of this embodiment is demonstrated. FIG. 3 shows an axial sectional view of the piston cooling jet of the present embodiment in the first valve closing state. FIG. 3 corresponds to FIG. As shown in FIG. 3, in the first valve closed state, the upward biasing force of the biasing member 5 (specifically, the first coil spring 52) is less than the downward pressing force due to the oil O hydraulic pressure. ,large. For this reason, the valve body 4 is raised with respect to the valve open state shown in FIG. The upper end of the valve body 4 is in contact with the stopper portion 201. As the valve body 4 rises, the first blocking portion 42 is disposed between the main body side flow path 20 and the nozzle side flow path 30 instead of the communication hole 41. For this reason, the main body side channel 20 and the nozzle side channel 30 are blocked. Therefore, the oil O does not flow from the main body side channel 20 to the nozzle side channel 30 in the first valve closed state. That is, the oil O is not injected to the piston 91 shown in FIG.

  In the first valve closing state, the urging member 5 includes a first spring portion 50 and a second spring portion 51. A first coil spring 52 is disposed in the first spring portion 50 when viewed from the radial direction. In the second spring portion 51, a first coil spring 52 and a second coil spring 53 are disposed in an overlapping manner. The first spring part 50 and the second spring part 51 are arranged in series in the vertical direction. Further, the first coil spring 52 and the second coil spring 53 of the second spring portion 51 are arranged in parallel in the radial direction.

  As described above, the second coil spring 53 has a larger spring constant than the first coil spring 52. For this reason, the second spring portion 51 has a larger spring constant than the first spring portion 50. In the valve open state shown in FIG. 2, the first spring portion 50 having a small spring constant is compressed by the pressing force of the oil O by the oil pressure. On the other hand, the second spring portion 51 having a large spring constant extends.

[Second valve closed state]
Next, the 2nd valve closing state of the piston cooling jet of this embodiment is demonstrated. FIG. 4 shows an axial sectional view of the piston cooling jet of the present embodiment in the second valve closing state. FIG. 4 corresponds to FIG. As shown in FIG. 4, in the second valve closed state, the downward pressing force due to the oil O hydraulic pressure is applied to the urging member 5 (specifically, the first coil spring 52 and the second coil spring 53). Greater than upward bias. Therefore, the valve body 4 is lowered with respect to the valve open state shown in FIG. That is, not only the first spring portion 50 having a small spring constant but also the second spring portion 51 having a large spring constant is compressed by the pressing force of the oil O by the oil pressure. When the valve body 4 is lowered, the second blocking portion 43 is disposed between the main body side channel 20 and the nozzle side channel 30 instead of the communication hole 41. For this reason, the main body side channel 20 and the nozzle side channel 30 are blocked. Therefore, the oil O does not flow from the main body side channel 20 to the nozzle side channel 30 in the second valve closed state. That is, the oil O is not injected to the piston 91 shown in FIG.

[Piston cooling jet movement when cold]
Next, the movement of the piston cooling jet of the present embodiment when it is cold (when the engine 9 shown in FIG. 1 is warmed up) will be described. FIG. 5 shows a correlation diagram between the engine speed during cold and the oil pressure of the main oil gallery. The temperature of the outside air is T = 20 ° C.

  When the engine 9 shown in FIG. 1 is started, as shown in FIG. 5, the engine speed rapidly increases from 0 rpm to about 1700 rpm between 0 seconds and 3 seconds. Further, the oil pressure of the oil O of the main oil gallery 900 shown in FIG. 1 increases rapidly from 0 kPa to about 410 kPa, as shown in FIG. This is because immediately after the engine 9 is started, the oil temperature of the oil O is low and the viscosity of the oil O is high. Note that, as indicated by a thin line in FIG. 5, when the temperature T of the outside air is lower (when the temperature is extremely low), the oil pressure of the oil O further increases.

  Between 3 seconds and 43 seconds after the engine 9 is started, the engine speed decreases from about 1700 rpm to about 1000 rpm. Further, the oil temperature of the oil O gradually rises and the viscosity of the oil O becomes low. For this reason, the oil pressure of the oil O falls from about 410 kPa to about 370 kPa.

  Between 43 seconds and 500 seconds after the engine 9 is started, the engine speed decreases from about 1000 rpm to about 700 rpm. Further, the oil temperature of the oil O is further increased, and the viscosity of the oil O is further decreased. For this reason, the oil pressure of the oil O rapidly decreases from about 370 kPa to about 170 kPa.

  Between 500 seconds and 1800 seconds after the engine 9 is started, the engine rotation speed remains at about 700 rpm. On the other hand, the oil temperature of the oil O further increases, and the viscosity of the oil O further decreases. For this reason, the oil pressure of the oil O falls from about 170 kPa to about 80 kPa.

  After 1800 seconds after the engine 9 is started, the engine rotation speed remains at about 700 rpm. Further, the oil pressure of the oil O remains about 80 kPa. In this way, warming up of the engine 9 is completed.

  In the cold state, the piston cooling jet 1 shown in FIG. 1 has the above-described valve opening state and the first valve closing state according to the balance between the urging force of the urging member 5 and the hydraulic pressure of the oil O. The state and the second valve closed state are switched.

  Specifically, when the hydraulic pressure is 170 kPa or more which is a low pressure side threshold value and 370 kPa or less which is a high pressure side threshold value, the piston cooling jet 1 is switched to the valve open state shown in FIG. In this case, the oil O is injected to the piston 91 shown in FIG.

  When the oil pressure is less than 170 kPa, the piston cooling jet 1 is switched to the first valve closing state shown in FIG. In this case, the oil O is not injected into the piston 91 shown in FIG.

  When the hydraulic pressure exceeds 170 kPa, the piston cooling jet 1 is switched to the second valve closing state shown in FIG. In this case, the oil O is not injected into the piston 91 shown in FIG.

  Thus, in the cold state, when the oil pressure of the oil O is less than the low-pressure side threshold value (= 170 kPa) and exceeds the high-pressure side threshold value (= 370 kPa), the injection of the oil O to the piston 91 is performed. Can be stopped.

[Piston cooling jet movement during warm]
Next, the movement of the piston cooling jet according to the present embodiment during warming (after completion of warming up of the engine 9 shown in FIG. 1) will be described. FIG. 6 shows a correlation diagram between the engine speed during warming and the oil pressure of the main oil gallery. The figure shows the case where the oil temperature T = 80 ° C. and the case where the oil temperature T = 100 ° C.

  When the engine speed increases, the oil pressure of the oil O in the main oil gallery 900 shown in FIG. 1 increases. When compared at the same engine speed, the oil pressure is higher when the oil temperature T is lower. The reason is that the lower the oil temperature T, the higher the viscosity of the oil O.

  When the oil temperature T = 80 ° C., the oil pressure becomes 170 kPa or more when the engine speed becomes 1700 rpm or more. For this reason, the piston cooling jet 1 is switched from the first valve closing state shown in FIG. 3 to the valve opening state shown in FIG. Therefore, the oil O is injected to the piston 91 shown in FIG.

  When the oil temperature T = 100 ° C., the oil pressure becomes 170 kPa or more when the engine speed becomes 2100 rpm or more. For this reason, the piston cooling jet 1 is switched from the first valve closing state shown in FIG. 3 to the valve opening state shown in FIG. Therefore, the oil O is injected to the piston 91 shown in FIG.

[Function and effect]
Next, the effect of the piston cooling jet of this embodiment is demonstrated. The piston cooling jet of this embodiment can be switched between a valve opening state shown in FIG. 2, a first valve closing state shown in FIG. 3, and a second valve closing state shown in FIG. As shown in FIG. 5, immediately after the start of the engine 9 in the cold state (between 3 and 43 seconds in FIG. 5), the viscosity of the oil O is high and the oil pressure of the oil O is excessively high (in FIG. 5). Over 370 kPa). Therefore, according to the conventional hydraulic valve mechanism of the piston cooling jet, the piston cooling jet is operated. That is, the oil O is injected into the piston 91 shown in FIG.

  In this regard, according to the piston cooling jet 1 of the present embodiment, not only the hydraulic pressure is low and the biasing force of the biasing member 5 exceeds the pressing force of the hydraulic pressure (first valve closing state shown in FIG. 3), Even in a state where the urging force of the urging member 5 is excessively high and lower than the hydraulic pressure (second valve closing state shown in FIG. 4), the main body side channel 20 and the nozzle side channel 30 can be blocked. it can. For this reason, even if the oil pressure of the oil O immediately after the start of the engine 9 is excessively high, the injection of the oil O to the piston 91 can be blocked by the second valve closing state.

  Thus, according to the piston cooling jet 1 of this embodiment, injection of the oil O at the time of cold can be controlled. For this reason, the temperature of the piston 91 can be raised quickly. In addition, overcooling of the piston 91 can be suppressed. Further, the warm-up of the engine 9 can be completed early. Further, since the highly viscous oil O does not easily fall on the crankshaft 93, it is possible to suppress an increase in the rotational resistance (stirring resistance against the oil O) of the crankshaft 93.

  Moreover, according to the piston cooling jet 1 of this embodiment, it is not necessary to arrange | position a temperature type valve mechanism or an electronically controlled valve mechanism. For this reason, the structure is simple and downsizing is possible.

  Further, as shown in FIG. 6, during the warm period, regardless of the oil temperature T, the hydraulic pressure does not exceed the high-pressure side threshold value (= 370 kPa) even if the engine speed increases to the upper limit. For this reason, the piston cooling jet 1 does not switch from the valve opening state shown in FIG. 2 to the second valve closing state shown in FIG. Therefore, during the warm period, the oil O can be injected to the piston 91 shown in FIG. 1 in the entire region where the hydraulic pressure is equal to or higher than the low pressure side threshold value (= 170 kPa).

  Moreover, according to the piston cooling jet 1 of this embodiment, as shown in FIG. 3, the 2nd spring part 51 is formed by the 1st coil spring 52 and the 2nd coil spring 53 being connected in parallel. Yes. The first spring portion 50 and the second spring portion 51 are connected in series. For this reason, from the formula (2), the spring constant of the second spring part 51 is larger than the spring constant of the first spring part 50. Therefore, from the formula (1), the first spring portion 50 is more easily deformed with respect to the hydraulic oil pressure of the oil O than the second spring portion 51.

  According to the piston cooling jet 1 of the present embodiment, the valve open state shown in FIG. 2 and the first shown in FIG. 3 are utilized by utilizing the difference in the degree of deformation between the first spring part 50 and the second spring part 51. The valve closing state and the second valve closing state shown in FIG. 4 can be switched. Specifically, the first valve closing state shown in FIG. 3 can be achieved by the first spring portion 50 and the second spring portion 51 not contracting. Moreover, when the 1st spring part 50 and the 2nd spring part 51 contract, the 2nd valve closing state shown in FIG. 4 can be achieved. Moreover, when the 1st spring part 50 shrink | contracts and the 2nd spring part 51 does not shrink | contract, the valve opening state shown in FIG. 2 can be achieved.

<Second embodiment>
The difference between the piston cooling jet of the present embodiment and the piston cooling jet of the first embodiment is that the biasing member includes a single coil spring. Here, only differences will be described.

  FIG. 7 shows an axial sectional view of the piston cooling jet of the present embodiment in the first valve closing state. In addition, about the site | part corresponding to FIG. 3, it shows with the same code | symbol. As shown in FIG. 7, the urging member 5 includes a single coil spring 54. The coil spring 54 includes a low spring portion 54a and a high spring portion 54b. The low spring portion 54a has a smaller spring constant than the high spring portion 54b. The low spring portion 54a is continuous below the high spring portion 54b. The first spring portion 50 having a small spring constant is constituted by a low spring portion 54a, and the second spring portion 51 having a large spring constant is constituted by a high spring portion 54b.

  When switching from the first valve closing state to the valve opening state (see FIG. 2), only the first spring portion 50 contracts and the second spring portion 51 does not contract. When switching from the open state to the second closed state (see FIG. 4), the first spring portion 50 and the second spring portion 51 contract.

  The piston cooling jet according to the present embodiment and the piston cooling jet according to the first embodiment have the same functions and effects with respect to the parts having the same configuration. As in the present embodiment, the urging member 5 may be configured by a single coil spring 54. In other words, the urging member 5 may have a plurality of spring portions regardless of the number of coil springs.

<Third embodiment>
The difference between the piston cooling jet of the present embodiment and the piston cooling jet of the first embodiment is that the biasing member includes a single coil spring. Further, the urging member urges the valve body by using a contraction force when returning from the extended state to the natural length state. Here, only differences will be described.

  FIG. 8 is a sectional view in the axial direction of the piston cooling jet of the present embodiment in the second valve closing state. In addition, about the site | part corresponding to FIG. 4, it shows with the same code | symbol. As shown in FIG. 8, the biasing member 5 includes a single coil spring 55. The upper end of the coil spring 55 is locked to the stopper 202. On the other hand, the lower end of the coil spring 55 is locked to the stopper 44. The coil spring 55 applies an urging force in the pulling direction (the direction of pulling upward) to the valve body 4.

  The coil spring 55 includes a low spring portion 55a and a high spring portion 55b. The low spring portion 55a has a smaller spring constant than the high spring portion 55b. The low spring portion 55a is continuous above the high spring portion 55b. The first spring portion 50 having a small spring constant is constituted by a low spring portion 55a, and the second spring portion 51 having a large spring constant is constituted by a high spring portion 55b.

  When switching from the second valve closing state to the valve opening state (see FIG. 2), only the second spring portion 51 contracts and the first spring portion 50 does not contract. When switching from the open state to the first closed state (see FIG. 3), the first spring portion 50 and the second spring portion 51 contract.

  The piston cooling jet according to the present embodiment and the piston cooling jet according to the first embodiment have the same functions and effects with respect to the parts having the same configuration. As in the present embodiment, the urging member 5 may urge the valve body 4 by using a contraction force when returning from the extended state to the natural length state. That is, the urging member 5 may pull the valve body 4.

<Others>
The embodiment of the piston cooling jet of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  In the above embodiment, as shown in FIGS. 5 and 6, the low-pressure side threshold is set to 170 kPa, and the high-pressure side threshold is set to 370 kPa. However, the set values of the low-pressure side threshold and the high-pressure side threshold are not particularly limited. For example, the low pressure side threshold value may be set to a hydraulic pressure at which the piston 91 is desired to be cooled during the warm time shown in FIG. Further, the high pressure side threshold value may be set to the hydraulic pressure that is reached in the cold state shown in FIG. 5 and that is not reached in the warm state shown in FIG.

  The number of arrangement and the positional relationship of the spring parts (first spring part 50, second spring part 51) of the biasing member 5 in the above embodiment are not particularly limited. The spring constants of the first coil spring 52 and the second coil spring 53 of the biasing member 5 of the first embodiment are not particularly limited. For example, the spring constants of the first coil spring 52 and the second coil spring 53 may be equal. Further, the first coil spring 52 may have a larger spring constant than the second coil spring 53. That is, the second spring portion 51 only needs to have a larger spring constant than the first spring portion 50. Further, the radial arrangement of the first coil spring 52 and the second coil spring 53 may be reversed.

  The setting method of the low spring portions 54a and 55a and the high spring portions 54b and 55b in the coil springs 54 and 55 of the biasing member 5 of the second embodiment and the third embodiment is not limited. By adjusting the diameter of the wire, the cross-sectional shape of the wire, the pitch between adjacent wires in the axial direction, the diameter of the spiral coil formed by the wire, etc., the low spring portions 54a and 55a and the high spring portion 54b, A difference in spring constant may be provided between the terminal 55b and 55b. The axial arrangement of the low spring portions 54a and 55a and the high spring portions 54b and 55b may be reversed.

  Moreover, you may comprise the spring parts (the 1st spring part 50, the 2nd spring part 51) of the biasing member 5 by springs (a leaf spring, a disc spring, an air spring, etc.) other than a coil spring. Moreover, you may comprise a spring part with elastic bodies, such as rubber | gum and an elastic foam.

1: piston cooling jet, 2: main body, 2a: accommodating chamber, 3: nozzle, 4: valve body, 5: biasing member, 9: engine.
20: Main body side channel, 21: Energizing member accommodating chamber, 30: Nozzle side channel, 40a: Spring seat, 40b: Spring seat, 41: Communication hole, 42: First blocking part, 43: Second blocking part 44: stopper, 50: first spring part, 51: second spring part, 52: first coil spring, 53: second coil spring, 54: coil spring, 54a: low spring part, 54b: high spring part, 55: Coil spring, 55a: Low spring part, 55b: High spring part, 90: Cylinder block, 91: Piston, 92: Connecting rod, 93: Crankshaft.
200a: spring seat, 200b: spring seat, 201: stopper portion, 202: stopper, 900: main oil gallery.
O: Oil.

Claims (5)

A body having a body-side flow path through which oil flows;
A nozzle having a nozzle-side flow path;
A valve body capable of communicating and blocking between the main body side channel and the nozzle side channel;
A biasing member that biases the valve body;
A piston cooling jet comprising:
The biasing member has a plurality of spring portions having different spring constants,
The valve body is driven by the urging force of the urging member and the hydraulic pressure of the oil,
A valve-open state in which the main body-side flow path and the nozzle-side flow path are communicated;
A first valve closed state in which the valve body moves when the biasing force exceeds the pressing force with respect to the valve open state, and the main body side flow path and the nozzle side flow path are blocked;
A second valve closing state in which the valve body moves when the urging force falls below the pressing force with respect to the valve open state, and the main body side flow path and the nozzle side flow path are blocked;
Piston cooling jet, which can be switched between The valve open state is a state in which the hydraulic pressure is not less than a low pressure side threshold value and not more than a high pressure side threshold value,
The first valve closed state is a state in which the hydraulic pressure is less than the low pressure side threshold value,
2. The piston cooling jet according to claim 1, wherein the second valve closing state is a state in which the hydraulic pressure exceeds the high pressure side threshold value. The main body has a storage chamber for storing the valve body in a reciprocable manner,
The valve body is disposed at one side of the communication hole that communicates the main body side flow path and the nozzle side flow path in the valve-opened state and in the reciprocating direction of the communication hole. A first blocking section that blocks the flow path and the nozzle-side flow path, and is arranged on the other side of the communication hole in the reciprocating direction to block the main-body-side flow path and the nozzle-side flow path in the second valve closed state The piston cooling jet according to claim 1, further comprising: a second blocking portion that performs the operation.   The piston cooling jet according to any one of claims 1 to 3, wherein the plurality of spring portions are arranged in series. The biasing member includes a first coil spring, and a second coil spring that is disposed on the radially outer side of the first coil spring and has a shorter axis than the first coil spring,
The plurality of spring portions are arranged such that the first coil spring is disposed alone, the first coil spring and the second coil spring are overlapped when viewed from the radial direction. The piston cooling jet according to claim 1, further comprising a second spring portion.

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