JP2017115922A - Bypass valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a bypass valve comprising a coil spring made of a shape memory alloy.SOLUTION: A bypass valve 1 is arranged at a connection portion between a bypass passage in which oil bypassing an oil cooler 1 flows, and an outlet side passage in which the oil passed through the oil cooler flows and, when the valve is closed, cuts off a flow of the oil from the bypass passage to the outlet side passage. The bypass valve 1 has a valve element 31 which receives force in the valve open direction from the oil in the bypass passage, and a coil spring 33 which is made of one shape memory alloy and always biases the valve element 31. The coil spring 33 biases the valve element 31 in the valve close direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a bypass valve that is arranged in a circuit that supplies oil to an oil cooler and that can bypass the oil supplied to the oil cooler.

  2. Description of the Related Art Conventionally, an oil cooler bypass valve using a spring made of a shape memory alloy is known.

  For example, in Patent Documents 1 and 2, a bypass having a first coil spring that biases the valve body in the valve closing direction and a second coil spring made of a shape memory alloy that causes the valve body to open in the valve opening direction. A valve is disclosed.

  In a conventional bypass valve using a shape memory alloy coil spring, when the oil temperature rises, the coil length of the second coil spring, which is a shape memory alloy coil spring, increases and the second coil spring closes. The biasing force in the valve direction becomes larger than the biasing force in the valve opening direction by the first coil spring, and the bypass valve is closed.

Japanese Utility Model Publication No. 2-114733 Japanese Utility Model Publication No. 63-78779

  However, in a conventional bypass valve using a shape memory alloy coil spring, in addition to a shape memory alloy coil spring that biases the valve body in the valve closing direction, the valve body is biased in the valve opening direction. Therefore, there is a problem that the bypass valve is increased in size and the degree of freedom in layout is reduced.

  The bypass valve of the present invention is disposed in a connecting portion between a bypass passage through which oil that bypasses the oil cooler flows and an outlet side passage through which oil that has passed through the oil cooler flows. Oil flow to the outlet side passage is blocked, and has a valve body that receives a force in the valve opening direction from the oil in the bypass passage, and a coil spring that constantly biases the valve body, The coil spring is only a coil spring made of one shape memory alloy that urges the valve body in the valve closing direction.

  The valve body has a cylindrical inner passage through which oil flows, and when the bypass valve is closed, the oil that has passed through the oil cooler flows through the inner passage. Good.

  The coil spring may be disposed in the internal passage.

  According to the present invention, since the coil spring for biasing the valve body is only one coil spring made of shape memory alloy, the bypass valve using the coil spring made of shape memory alloy can be miniaturized, The degree of freedom in layout can be improved.

  The coil spring used for the bypass valve is made of a shape memory alloy, so that the spring constant of the coil spring at a high temperature can be relatively increased, and the oil pressure in the bypass passage and the oil in the outlet side passage can be increased. In addition to the pressure difference from the pressure, the bypass valve can be opened and closed depending on the temperature of the oil.

  In addition, if a coil spring made of shape memory alloy is placed in the internal passage of the valve body through which oil flows, the temperature of the coil spring can quickly follow the change in the temperature of the oil, and the temperature of the oil can be controlled. Accordingly, the bypass valve can be opened and closed with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS The 1st Example of the bypass valve which concerns on this invention is shown typically with the oil bypass structure of an oil cooler, Comprising: Sectional drawing of the principal part at the time of bypass valve closing. BRIEF DESCRIPTION OF THE DRAWINGS The 1st Example of the bypass valve which concerns on this invention is shown typically with the oil bypass structure of an oil cooler, Comprising: Sectional drawing of the principal part at the time of bypass valve opening. The perspective view of the bypass valve in 1st Example. Sectional drawing of the bypass valve in 1st Example. Explanatory drawing which notched and showed a part of bypass valve in 1st Example. Explanatory drawing explaining the outline of the spring characteristic of the coil spring made from a shape memory alloy used for the bypass valve which concerns on this invention. The perspective view of the bypass valve in 2nd Example. Sectional drawing of the bypass valve in 2nd Example. Explanatory drawing which notched and showed a part of bypass valve in 2nd Example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 schematically show the bypass valve 1 of the first embodiment together with the oil bypass structure of the oil cooler 2, and FIG. 1 is a cross-sectional view when the bypass valve 1 is closed. 2 is a sectional view when the bypass valve 1 is opened. In the following description, for convenience of explanation, terms such as “upper”, “lower”, “top”, and “bottom” are used with reference to the postures of FIGS. 1 and 2, but an actual oil cooler is used. At the time of use of 2, it is not limited to the attachment posture of FIG. 1, FIG. Moreover, in FIG. 1, FIG. 2, hatching is abbreviate | omitted with respect to the cross section of a one part member for convenience.

  The oil cooler 2 cools engine oil of an automobile by heat exchange with cooling water, and is directly attached to a cylinder block 3 of an internal combustion engine as a block.

  The oil cooler 2 is attached to a heat exchanging unit 4 that exchanges heat between oil and cooling water, a relatively thick top plate 5 that is attached to the upper surface of the heat exchanging unit 4, and a lowermost surface of the heat exchanging unit 4. A first bottom plate 6, a relatively thick second bottom plate 7 attached to the lower surface of the first bottom plate 6 and fixed to the oil cooler mounting surface 8 of the cylinder block 3 by bolts (not shown); It is roughly composed of

  The heat exchanging unit 4 is configured by laminating a large number of shallow dish-shaped core plates 9 having the same basic shape with the fin plate 10 together with the fin plate 10, so that the oil flow between the two adjacent core plates 9, 9 is reduced. The paths 11 and the cooling water flow paths 12 are configured alternately. The core plate 9 actually includes a plurality of types of core plates 9 having different details, and these are appropriately combined.

  The multiple core plates 9, multiple fin plates 10, top plate 5, first and second bottom plates 6, 7 are joined and integrated together by brazing. Specifically, each of these parts is formed using a so-called clad material in which a brazing material layer is coated on the surface of an aluminum alloy base material, and each part is temporarily assembled at a predetermined position and heated in a furnace. Thus, it is brazed together.

  The first bottom plate 6 is located between the lowermost surface of the heat exchange unit 4 and the second bottom plate 7. The first bottom plate 6 is formed with a first through hole 15 having a long hole shape along a diagonal line of the first bottom plate 6. The first through hole 15 communicates with an oil introduction port 16 formed on the lowermost surface of the heat exchange part 4 at one end side and communicates with an oil discharge port 17 formed at the lowermost surface of the heat exchange part 4 on the other end side. It is formed as follows. The first through hole 15 constitutes a bypass passage 18 through which the oil bypassing the heat exchange unit 4 flows together with the lowermost surface of the heat exchange unit 4 and the upper surface of the second bottom plate 7. The bypass passage 18 is parallel to the oil cooler mounting surface 8 of the cylinder block 3 to which the oil cooler 2 is mounted.

  The second bottom plate 7 has a second oil inlet side through hole 21 having a circular cross section through which oil introduced into the oil flow path 11 in the heat exchange section 4 flows, and the oil flow path 11 in the heat exchange section 4. A second oil outlet side through hole 22 having a circular cross section through which oil discharged from the oil flows is formed. The second oil inlet-side through hole 21 communicates with a block-side oil introduction path 23 formed in the cylinder block 3 at the lower end and one end of the first through hole 15 formed at the upper end in the first bottom plate 6. Communicate with the side. The second oil outlet side through hole 22 communicates with the block side oil discharge passage 24 formed at the cylinder block 3 at the lower end, and the first through hole 15 formed at the first bottom plate 6 at the upper end. It communicates with the end side.

  The oil introduction port 16 of the heat exchanging unit 4 has an inlet side passage 25 configured by a block side oil introduction passage 23, a second oil inlet side through hole 21, a portion on one end side of the first through hole 15, and the like. Oil is introduced. Moreover, from the oil discharge port 17 of the heat exchange part 4, the exit comprised by the part of the other end side of the 1st through-hole 15, the 2nd oil exit side through-hole 22, and the block side oil discharge path 24 grade | etc.,. Oil is discharged into the side passage 26.

  Although not shown, the first and second bottom plates 6 and 7 have a passage hole through which the cooling water introduced into the cooling water passage 12 in the heat exchanging section 4 flows, and the heat exchanging section 4. A passage hole through which the cooling water discharged from the cooling water flow path 12 flows is formed.

  The block-side oil discharge passage 24 formed in the cylinder block 3 includes a circular cross-section upstream hole 27 located on the oil cooler mounting surface 8 side, and a circular cross-section downstream hole connected to the upstream hole 27. Part 28.

  The upstream hole 27 is formed so that its inner diameter is larger than the outer diameter on the lower end side of the bypass valve 1, and its central axis is perpendicular to the oil cooler mounting surface 8. The downstream hole 28 has an inner diameter smaller than the inner diameter of the upstream hole 27.

  In FIG. 1 and FIG. 2, 29 is a sealing material for sealing the periphery of the second oil inlet side through hole 21 on the oil cooler mounting surface 8, and 30 is a second oil outlet side through hole on the oil cooler mounting surface 8. 22 is a sealing material for sealing the periphery of 22. Further, the width of the first through hole 15 is formed larger than the diameters of the oil introduction port 16, the oil discharge port 17, the second oil inlet side through hole 21, and the second oil outlet side through hole 22. Therefore, in the assembled state, the oil introduction port 16, the oil discharge port 17, the second oil inlet side through hole 21, and the second oil outlet side through hole 22 are located inside the first through hole 15.

  The bypass valve 1 is disposed in the outlet side passage 26 through which the oil that has passed through the oil cooler 2 flows. As shown in FIGS. 3 to 5, the bypass valve 1 includes a stepped cylindrical valve body 31, a casing 32 in which the valve body 31 is housed, a casing 32, and the valve body 31 in a valve closing direction ( And a coil spring 33 made of a shape memory alloy that is always urged to the upper side in FIGS. That is, the bypass valve 1 has only a coil spring 33 made of a shape memory alloy as a coil spring that constantly biases the valve body 31.

  The valve body 31 is made of, for example, a resin material, and an internal passage 34 through which oil flows along the axial direction of the valve body 31 (the vertical direction in FIGS. 1 and 2) is formed. This valve body 31 has an upper end portion 35 having a relatively small diameter and a lower end portion 36 having a relatively large diameter, and on the inner and outer periphery of a portion where the upper end portion 35 and the lower end portion 36 are continuous, A valve body peripheral side step surface 37 and a valve body outer peripheral side step surface 38 which are continuous over the entire circumference are formed. The valve body outer peripheral step surface 38 is a pressure receiving surface that receives force in the valve opening direction (downward in FIGS. 1 and 2) of the valve body 31 from the oil in the bypass passage 18.

  Here, the valve closing direction and the valve opening direction of the valve body 31 are respectively along the axial direction of the valve body 31.

  The valve body 31 is formed with an annular projecting wall 39 that is continuous over the entire circumference on the inner circumference of the upper end 35. The inner peripheral side of the protruding wall 39 is an opening on the upper end side of the valve body 31. In other words, the valve body 31 is formed in a stepped bottomed cylindrical shape, and a through hole is formed in the bottom wall located on the upper end side.

  The inner surface of the valve body peripheral side step surface 37 and the protruding wall 39 is a pressure receiving surface that receives the force in the valve closing direction of the valve body 31 from the oil in the internal passage 34.

  The casing 32 is made of a resin material, and includes a bottomed cylindrical upper casing 41 that houses the valve body 31 and a stepped bottomed cylindrical lower casing 42.

  The upper casing 41 has an upper end opening 44 formed of a through-hole having a circular cross section that allows the oil discharge port 17 and the internal passage 34 of the valve body 31 to communicate with each other at the center of the bottom wall 43 on the upper end side against which the upper end of the valve body 31 is pressed. Is formed. In the upper casing 41, a plurality of side openings 46 are formed on the upper end side of the side wall 45 by a plurality of through holes along the circumferential direction. The pressure of the oil in the bypass passage 18 acts on the valve body outer peripheral side step surface 38 of the valve body 31 from the side opening 46.

  The inner diameter of the upper casing 41 is set so that the lower end portion 36 of the valve body 31 can slide. That is, the inner diameter of the upper casing 41 is set to have a predetermined clearance from the lower end portion 36 of the valve body 31.

  The lower casing 42 includes a large-diameter portion 47 on the upper end side having a relatively large diameter and a small-diameter portion 48 on the lower end side having a relatively small diameter, and the large-diameter portion 47 and the small-diameter portion 48 are continuous. A casing inner peripheral side step surface 49 and a casing outer peripheral side step surface 50 that are continuous over the entire periphery are formed on the inner and outer periphery of the portion to be formed.

  In the lower casing 42, the small diameter portion 48 has a bottom wall 51, and a lower end opening 52 formed of a through hole having a circular cross section is formed at the center of the bottom wall 51. Further, the inner diameter of the small diameter portion 48 of the lower casing 42 is set to be smaller than the inner diameter of the lower end portion 36 of the valve body 31.

  The lower end side of the upper casing 41 is inserted into the large-diameter portion 47 of the lower casing 42, and the protrusion 53 on the outer periphery of the lower end of the upper casing 41 engages with the opening 54 of the large-diameter portion 47 of the lower casing 42 so that both are fixed. Has been. In other words, the upper casing 41 and the lower casing 42 are connected to each other by a snap fit.

  The coil spring 33 is made of, for example, a Ni—Ti-based alloy containing nickel and titanium, and is set so that the transformation temperature is approximately a predetermined temperature between 60 ° C. and 100 ° C. The coil spring 33 is disposed on the inner peripheral side of the valve body 31 and the casing 32, and is sandwiched between the protruding wall 39 of the valve body 31 and the bottom wall 51 on the lower end side of the lower casing 42. The coil spring 33 is located in the internal passage 34 of the valve body 31 and is in direct contact with the oil flowing through the fluid passage 34.

  The bypass valve 1 is inserted into the oil cooler 2 from the second oil outlet side through hole 22 of the second bottom plate 7 at the upper end side, and the bottom wall 43 at the upper end of the upper casing 41 is in close contact with the lowermost surface of the heat exchange unit 4 Thus, the protrusion 55 on the outer peripheral side of the upper end of the large diameter portion 47 of the lower casing 42 is engaged with the upper opening edge of the second oil outlet side through hole 22 to be fixed to the oil cooler 2.

  At this time, the oil discharge port 17 and the upper end opening 44 are overlapped. Further, the upper end side of the bypass valve 1 is disposed in the bypass passage 18. That is, the bypass valve 1 is disposed at a connection portion between the outlet side passage 26 and the bypass passage 18, and the bypass passage 18 is connected from a direction perpendicular to the axis of the valve body 31. In other words, the bypass passage 18 is connected to the bypass valve 1 from a direction orthogonal to the advancing / retreating direction of the valve body 31.

  The lower end side of the bypass valve 1 is accommodated in the upstream hole 27 of the block side oil discharge passage 24 when the oil cooler 2 is attached to the cylinder block 3.

  The sliding movement of the valve body 31 in the valve opening direction is regulated by the lower end of the lower end portion 36 of the valve body 31 abutting against the casing inner circumferential side step surface 49. The internal passage 34 of the valve body 31 is in a state where oil always flows regardless of the open / closed state of the bypass valve 1 and substantially functions as a part of the outlet side passage 26.

  Here, the outline of the spring characteristic of the coil spring 33 used for the bypass valve 1 is demonstrated using FIG.

  Since the coil spring 33 is made of a shape memory alloy, the spring constant at high temperature is larger than that at low temperature.

  When a load is applied to the coil spring 33 at a high temperature, the coil length is shortened according to the applied load, and when the applied load is removed (released), the coil length returns to the length before the load is applied. That is, when the applied load is removed, the coil spring 33 at a high temperature basically has no distortion.

  The coil spring 33 at a low temperature is greatly distorted even at a low load, and the strain remains even after the load is removed. That is, when a predetermined load A (low load) is applied to the coil spring 33 at a low temperature, the coil length is shortened according to the applied load A. However, even if the applied load A is removed (released). The coil length does not return to the length before applying the load A (coil length at high temperature). When the same load A is applied again after removing the applied load A, the coil spring 33 is shortened to the coil length when the previous load A was applied. However, even if the applied load A is removed again, the previous load The coil length of the coil spring 33 is returned only to the coil length when A is removed. And the coil spring 33 of such a state (state in which distortion remained) can be returned to the coil length at the time of high temperature by heating.

  Next, the operation of the bypass valve 1 will be described.

  If there is no clogging or the like in the oil flow path 11 in the heat exchanging section 4, the pressure difference between the pressure of oil flowing through the internal passage 34 of the valve body 31 and the pressure of oil in the bypass passage 18 communicating with the inlet side passage 25 Is basically smaller. That is, the pressure of oil in the bypass passage 18 that acts on the valve body outer peripheral side step surface 38 and urges the valve body 31 in the valve opening direction, and the inner surface of the valve body peripheral side step surface 37 and the protruding wall 39. Thus, the pressure difference from the oil pressure in the internal passage 34 that urges the valve body 31 in the valve closing direction is basically reduced.

  Therefore, the bypass valve 1 is closed as shown in FIG. 1 unless the pressure of the oil flowing through the internal passage 34 of the valve body 31 is relatively lowered. At this time, the valve body 31 is pressed against the bottom wall 43 of the upper casing 41 in the valve closing direction by the urging force of the coil spring 33, and oil does not flow from the bypass passage 18 to the outlet side passage 26. That is, when the bypass valve 1 is closed, the oil flow from the bypass passage 18 to the outlet side passage 26 is blocked by the valve body 31. Since the internal passage 34 is directly continuous with the oil discharge port 17 of the heat exchange unit 4, the oil flowing through the inlet side passage 25 always flows into the outlet side passage 26 through the heat exchange unit 4, and heat exchange is performed. The oil is cooled according to the performance of the part 4.

  When clogging or the like occurs in the oil flow path 11 in the heat exchanging section 4 and the pressure loss increases, the pressure of the oil flowing through the internal passage 34 of the valve body 31 relatively decreases. That is, the pressure of the oil in the bypass passage 18 acting on the valve body outer peripheral side step surface 38 and urging the valve body 31 in the valve opening direction is applied to the inner surface of the valve body peripheral side step surface 37 and the protruding wall 39. The pressure of the oil in the internal passage 38 that acts to urge the valve body 31 in the valve closing direction becomes larger.

  Therefore, when the pressure of the oil in the bypass passage 18 acting on the valve body outer circumferential side step surface 38 becomes larger than the urging force of the coil spring 33, the bypass valve 1 is opened as shown in FIG. At this time, the valve body 31 is slid in the valve opening direction, and the internal passage 34 of the valve body 31 and the bypass passage 18 communicate with each other. Then, the oil in the inlet-side passage 25 flows into the bypass passage 18 so as to bypass the heat exchange section 4 and flow into the outlet-side passage 26, and the oil pressure in the inlet-side passage 25 becomes excessively high. It is avoided.

  When the temperature of the oil is low, the viscosity of the oil becomes high, and the flow resistance when the oil flows through the oil cooler 2 becomes relatively large. That is, when the temperature of the oil decreases, the pressure loss in the oil cooler 2 becomes relatively large, and the oil pressure in the bypass passage 18 becomes higher than the oil pressure in the outlet side passage 26.

  Therefore, when the temperature of the oil is low, the spring constant of the coil spring 33 may be small, and the bypass valve 1 is opened as shown in FIG.

  When the temperature of the oil is high, the viscosity of the oil becomes low, and the flow resistance when the oil flows through the oil cooler 2 becomes relatively small. That is, when the temperature of the oil increases, the pressure loss of the oil cooler 2 becomes relatively small, and the pressure difference between the oil pressure in the bypass passage 18 and the oil pressure in the outlet side passage 26 becomes small.

  Therefore, when the oil temperature is high, the spring constant of the coil spring 33 may be large, and the bypass valve 1 is basically closed as shown in FIG.

  In such a bypass valve 1 of the first embodiment, the coil spring for biasing the valve body 31 is only one coil spring 33 made of a shape memory alloy, and therefore the coil spring 33 made of a shape memory alloy is used. The bypass valve 1 can be reduced in size, and the degree of freedom in layout can be improved.

  Further, by making the coil spring 33 made of a shape memory alloy, the spring constant of the coil spring 33 at a high temperature can be relatively increased, and the oil pressure in the bypass passage 18 and the oil in the outlet side passage 26 can be increased. In addition to the pressure difference from the pressure, the bypass valve 1 can be opened and closed depending on the temperature of the oil. More specifically, when the temperature of the oil is low, the bypass valve 1 can be opened to allow the bypass passage 18 and the outlet side passage 26 to communicate, and the oil cooler 2 can be bypassed to allow the oil to flow therethrough. Become. When the temperature of the oil is high, it is basically possible to close the bypass valve and cool the oil with an oil cooler.

  And since the coil spring 33 is arrange | positioned in the internal channel | path 34 of the valve body 31, the temperature of the coil spring 33 can be made to track the temperature change of oil rapidly, and it is a bypass valve accurately according to the temperature of oil. 1 can be opened and closed.

  Next, another embodiment of the present invention will be described. The same components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description will be omitted.

  7 to 9 show the bypass valve 62 of the second embodiment of the present invention. The bypass valve 62 has substantially the same configuration as the bypass valve 1 of the first embodiment described above, but the bypass valve 62 of the second embodiment is an upper casing of the bypass valve 1 of the first embodiment described above. 41 is omitted.

  That is, in the second embodiment, the bypass valve 62 includes a stepped bottomed cylindrical casing 42 in which the valve body 31 and a coil spring 33 made of a shape memory alloy are housed. It is configured to be pressed directly against the bottom surface.

  Also in the second embodiment, it is possible to obtain substantially the same operational effects as those of the first embodiment described above.

  Further, the second embodiment has an advantage that the number of parts of the bypass valve 62 can be relatively reduced.

DESCRIPTION OF SYMBOLS 1 ... Bypass valve 31 ... Valve body 32 ... Casing 33 ... Coil spring 34 ... Internal passage

Claims (3)

It is arranged at the connection part between the bypass passage through which the oil bypassing the oil cooler flows and the outlet side passage through which the oil that has passed through the oil cooler flows. In the bypass valve that shuts off the flow,
A valve body that receives force in the valve opening direction from the oil in the bypass passage, and a coil spring that constantly biases the valve body,
2. The bypass valve according to claim 1, wherein the coil spring is only a coil spring made of one shape memory alloy that urges the valve body in a valve closing direction. The valve body has a cylindrical shape and has an internal passage through which oil flows.
A bypass valve characterized in that when the bypass valve is closed, oil that has passed through the oil cooler flows through the internal passage.   The bypass valve according to claim 2, wherein the coil spring is disposed in the internal passage.

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