JP2015161275A - Thermo valve device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve freedom in design or attain a smooth motion in a thermo valve device with a bypass valve body.SOLUTION: A thermo valve device 4 has a fixed shaft 12 and a movable cylinder 13. The movable cylinder 13 is provided with a main valve body 15 and a large-diameter part (a thermosensitive member storing part) 13b. A bypass passage 9 is opened to a valve chamber 3 under a state in which it is substantially opposing against a main passage 6, and a bypass valve body 18 closing the bypass passage 9 is slidably fitted to the movable cylinder 13. The bypass valve body 18 is formed as one having a protrusion part 18b protruded to a side opposite to the bypass passage 9 and the movable cylinder 13 is slidably held by the protrusion part 18b. Since it is possible to make an advancing size of the movable cylinder 13 into the bypass passage 9, a freedom in design of a cylinder head 1 is high. Since a length of the movable cylinder 13 is made short and at the same time a rigidity of the bypass valve body 18 becomes high, a guiding function of the movable cylinder 13 is also improved.

Description

  The present invention relates to a thermo valve device (temperature sensing valve device) used for controlling the flow of cooling water in an internal combustion engine.

  In a water-cooled internal combustion engine for a vehicle, a thermo valve device provided with a temperature sensitive member is provided in a cylinder head in order to control the flow of cooling water in accordance with the temperature of the engine. That is, the cooling water generally cools the cylinder head regardless of the temperature and flows to the heater. However, if the water temperature is lower than the predetermined temperature, the cooling water does not circulate through the radiator, and if the water temperature exceeds the predetermined temperature, the cooling water Is automatically controlled by a thermo-valve device to circulate through the radiator.

  This thermo-valve device has a fixed shaft that is fixedly disposed in the valve chamber, and a movable cylinder that is slidably fitted on the fixed shaft, and a radiator is disposed at one end of the movable cylinder. A main valve body that opens and closes the return passage is integrally provided, and the temperature sensing member expands and contracts by the heat of the cooling water, so that the movable cylinder moves the fixed shaft to open and close the main valve body.

  As a cooling water control method for the internal combustion engine, a bypass passage is provided for communicating the jacket of the cylinder head and the valve chamber, and the cooling water leaks to the valve chamber when the pressure of the cooling water in the jacket exceeds a predetermined value. In this case, the bypass passage is open to the opposite side of the main passage, and the bypass valve body is slidably fitted to the other end of the movable cylinder, and the movable cylinder and the bypass valve body In between, the spring which urges | biases a bypass valve body toward a bypass channel | path is arrange | positioned.

  For example, as disclosed in Patent Document 1, the bypass valve body has a simple flat plate shape, and the movable cylinder is slidable in a hole (burring portion) provided in the center of the bypass valve body. It is fitted.

JP2013-241918A

  The bypass valve element also serves as a guide member for holding the movable cylinder, and the main cylinder opens when the movable cylinder moves to the bypass passage side due to the expansion of the temperature-sensitive member. Is only a flat form, the other end of the movable cylinder is located at the opening of the bypass passage in the closed state of the main valve body, so that when the movable cylinder moves due to the expansion of the temperature sensitive member The other end of the movable cylinder will greatly enter the inside of the bypass passage.

  In this case, there is no particular problem if the bypass passage is deep in the axial direction of the movable cylinder, but there is a case where the bottom surface of the bypass passage has to be made shallow due to the size of the cylinder head, etc. There is a risk of collision with the bottom surface of the valve body. In order to avoid this, it is necessary to deepen the position of the bottom surface of the bypass passage, or to shift the thermo valve device itself away from the bypass valve body, and in any case, the design becomes very troublesome.

  In addition, since the length of the movable cylinder is increased, a twist occurs between the bypass valve body and the movable cylinder, and the smooth movement of the movable cylinder may be impaired. Further, the dynamic pressure of the cooling water in the bypass passage acts intensively on a part of the bypass valve body and the bypass valve body is inclined, and as a result, the movement of the bypass valve body may be easily twisted. is there.

  The present invention has been made to improve the current situation.

  The present invention has a fixed shaft that is immovably disposed in the valve chamber, and a movable cylinder (sliding body) that is slidably fitted on the fixed shaft, and one end side of the movable cylinder. Is provided with a main valve body that opens and closes the main passage by sliding the movable cylinder on the fixed shaft by the expansion and contraction of the temperature sensitive member, A bypass valve body that closes the bypass passage is slidably fitted from the outside, and the bypass valve body is biased by a spring in a direction to close the bypass passage. The protrusion has a protruding shape that protrudes on the opposite side of the passage, and the protrusion is fitted into the movable cylinder.

  In the present invention, since the bypass valve body has a convex shape protruding toward the main valve body, the portion of the bypass valve body that holds the movable cylinder slidably is separated from the opening surface of the bypass passage. Can do. For this reason, even if the movable cylinder moves due to the expansion of the temperature-sensitive member, the movable cylinder can be prevented from entering the bypass passage deeply. That is, a state in which the movable cylinder does not enter the bypass passage at all or a state in which the movable cylinder enters the bypass passage little can be achieved.

  Therefore, the structure of the bypass passage is not affected by the movable cylinder, and the design freedom of the cylinder head can be improved. Moreover, since it is not necessary to change the arrangement position of the thermo-valve device, the design effort does not increase. Furthermore, since the movable cylinder can be made shorter than before, and the rigidity of the bypass valve body is improved and the support function of the movable cylinder is improved, the smoothness of movement of the movable cylinder is improved. Reliability can be improved.

  Furthermore, if the protrusion part of the bypass valve body is configured in a cup shape, the cooling water can evenly act on the inner surface of the protrusion part, so that the posture of the bypass valve body can be stabilized. The function of pushing the bypass valve body in the axial direction with water is greatly improved. As a result, it is possible to improve the bypass function by pushing the bypass valve body without twisting. If the protrusion is formed in a cup shape, the spring can be prevented from shifting, but this also contributes to the smooth movement of the bypass valve body.

It is sectional drawing of embodiment. It is sectional drawing of the state which opened the main valve body. (A) is sectional drawing of the state which the bypass valve body opened, (B) is another example figure of the bypass valve body 18. FIG.

(1). First Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is applied to a thermo valve device for a vehicle internal combustion engine. Therefore, the cooling water sent from the jacket of the engine body (cylinder head) to the heater for heating the vehicle returns to the thermo valve device.

  In the present embodiment, a valve chamber 3 is constituted by the cylinder head 1 and the substantially cylindrical housing 2, and a thermo valve device 4 is disposed in the valve chamber 3. The valve chamber 3 is long in the direction (lateral direction) orthogonal to the side surface of the cylinder head 1, and the housing 2 has a radiator return passage 5 protruding to the opposite side of the cylinder head 1 and the longitudinal direction of the valve chamber 3. And a heater return passage 6 opened in a direction orthogonal to. Although not shown, the discharge passage toward the water pump opens in a direction perpendicular to the paper surface.

  The radiator return passage 5 corresponds to the main passage described in the claims, and a radiator return pipe 7 is connected to the inlet hole thereof. A heater return pipe 8 is connected to the heater return passage 6.

  A bypass passage 9 is opened on the bottom surface 3 a of the valve chamber 3 in the cylinder head 1 so as to face the radiator return passage 5. The bypass passage 9 has an L shape and opens to the valve chamber 3 in a different direction. The opening surface of the bypass passage 9 is circular, and the shaft center 10 and the shaft center 11 of the radiator return passage 5 are offset (offset) by a slight dimension E, and the heater return passage 6 is a bypass passage. 9 is arranged in a direction in which the axis 11 of the radiator return passage 5 is shifted with respect to the axis 10 of the reference numeral 9.

  The thermo valve device 4 includes a fixed shaft 12 concentrically disposed with the axis 10 of the bypass passage 9 and a movable cylinder (cylindrical slide body) 13 slidably fitted on the fixed shaft 12. One end 12a of the fixed shaft 12 positioned on the side of the radiator return passage 5 is held by the first bracket 14, and the first bracket 14 is fixed to the housing 2 via a seal ring. Therefore, the fixed shaft 12 is held so as not to move in the axial direction.

  The first bracket 14 has a flange portion 14a fixed to the housing 2 and a convex portion 14b that grips the fixed shaft 12, and the convex portion 14b has a large hole penetrating inside and outside. . Accordingly, the cooling water can flow into the bracket 14.

  The movable cylinder 13 is integrally formed with a main valve body 15 that comes into contact with the flange portion 14a of the first bracket 14 (the main valve body 15 may be configured separately and fixed to the movable cylinder 13). Good.) Accordingly, the flange portion 14a of the first bracket 14 functions as a valve seat against which the main valve element 15 is abutted.

  Furthermore, the movable cylinder 13 is provided with a large-diameter portion (temperature-sensitive portion) 13b that covers the temperature-sensitive member, and an inwardly curled portion 16a at the tip of the second bracket 16 fixed to the flange portion 14a of the first bracket 14. Is fitted to the meridian portion 13b so as to be slidable from the outside. A first spring 17 is disposed between the inwardly curled portion 16 a of the second bracket 16 and the main valve body 15. Therefore, the movable cylinder 13 can move forward against the first spring 17. Then, the main valve body 15 is separated from the first bracket 14, and the cooling water flows from the radiator return passage 5 into the discharge port.

  The large-diameter portion 13 b of the movable cylinder 13 is positioned at the opening portion of the heater return passage 6. For this reason, the temperature-sensitive member (for example, temperature-sensitive wax) built in the large-diameter portion 13b returns from the heater return passage 6 and expands / contracts by the heat of the cooling water, whereby the movable cylinder 13 moves in the axial direction.

  The bypass passage 9 is closed by a bypass valve body 18 from the valve chamber 3 side. The bypass valve element 18 has a circular shape that is concentric with the movable cylinder 13 and the bypass passage 9, and has a flange portion 18 a that abuts against the seating surface 19 at the opening edge of the bypass passage 9, and a cup-like shape that protrudes toward the movable cylinder 13. The burring part 18c is provided in the bottom part of the protrusion part 18b, and the movable cylinder 13 is slidably inserted in this burring part 18c. A cylindrical rib 18d facing the movable cylinder 13 is formed on the outer periphery of the flange portion 18a. The peripheral wall of the protrusion 18 b is tapered toward the movable cylinder 13.

  A second spring 20 of a compression coil spring type is disposed between the large diameter portion 13 b of the movable cylinder 13 and the flange 18 a of the bypass valve body 18. The movable cylinder 13 is formed with an intermediate diameter portion 13 c for preventing the second spring 20 from shifting. The spring force of the second spring 20 is weaker than the spring force of the first spring 17. Therefore, both the movement of the movable cylinder 13 and the movement of only the bypass valve body 18 without the movement of the movable cylinder 13 are permitted.

  Of the inner surface of the valve chamber 3, a volume part (expansion part) 21 with the inner side faced is provided on the inner side part provided with the heater return path 6 on the back side of the heater return path 6.

  In the above configuration, the cooling water returned from the heater return passage 6 always flows into the valve chamber 3, and the thermo valve device 4 operates by detecting the temperature of the cooling water. That is, when the temperature of the cooling water reaches a predetermined value or more, as shown in FIG. 2, the cooling water flows from the radiator return passage 5 to the discharge passage by moving toward the bypass valve body 18 and opening the main valve body 15.

  Even if the temperature of the cooling water is equal to or lower than the predetermined value, if the pressure of the cooling water in the jacket of the cylinder head 1 becomes higher than the predetermined value, as shown in FIG. 18 is pushed away, flows into the valve chamber 3 and is discharged from the discharge port.

  And since it protrudes on the opposite side to the bypass passage 9 of the bypass valve body 18, the support part of the movable cylinder 13 by the bypass valve body 18 is also separated from the bypass passage 9, and even if the bypass passage 9 is shallow, The function as the thermo-valve device 4 can be reliably exhibited by moving the movable cylinder 13 by a necessary amount. Therefore, the bypass passage 9 can be formed in an L shape without being restricted by the movable cylinder 13.

  In addition, the movable cylinder 13 can be made shorter than before, and the rigidity of the bypass valve body 18 is increased and the support function of the movable cylinder 13 is improved, so that the movement of the movable cylinder 13 can be improved smoothly. Further, when the bypass valve body 18 is opened with cooling water, the protrusion 18b has a tapered cup shape, so that the cooling water acts on the inner surface of the bypass valve body 18 with an equal pressure. The posture of the body 18 is stable, and the bypass valve body 18 can be moved smoothly. As a result, it is possible to improve the bypass function by pushing the bypass valve body 18 without twisting.

  In the present embodiment, the thermo valve device 4 is displaced (offset) from the heater return passage 6 with respect to the axial center of the valve chamber 3, but if configured in this way, the thermo valve device 4 is discharged from the heater return passage 6. Since the cooled water is uniformly applied to the large-diameter portion 13b in which the temperature sensitive member is built in the thermo valve device 4, there is an advantage that the temperature responsiveness to the cooling water can be improved.

  Furthermore, in the present invention, the volume portion 21 is provided near the heater return passage 6. However, since the volume portion 21 plays a role of retaining the cooling water that has come out of the heater return passage 6, the response of the temperature-sensitive member. Property can be further improved.

  As shown in FIG. 3B, the projecting portion 18b can be formed in a simple cylindrical shape. Furthermore, the present invention can be embodied in various ways. For example, the unit having the valve chamber 3 may be configured separately from the cylinder head, and a thermo valve device may be attached thereto. Alternatively, conversely, a heater return passage or the like can be provided in the cylinder head.

  The present invention can actually be embodied in a thermo valve device. Therefore, it can be used industrially.

1 Cylinder head 2 Housing (case)
3 Valve chamber 4 Thermo-valve device 5 Radiator return passage (main passage)
6 Heater return passage 9 Bypass passage 12 Fixed shaft 13 Movable cylinder 14 First bracket 15 Main valve body 16 Second bracket 17 First spring 18 Bypass valve body 18a Flange portion 18b Protruding portion 19 Seat surface 20 Second spring

Claims (1)

A fixed shaft that is immovably disposed in the valve chamber; and a movable cylinder that is slidably fitted on the fixed shaft. The movable cylinder is sensitive to one end of the movable cylinder. While a main valve body that opens and closes the main passage by sliding on the fixed shaft by expansion and contraction of the temperature member is provided, a bypass valve body that closes the bypass passage is provided on the other end side of the movable cylinder. It is slidably fitted from the outside, and the bypass valve body is biased by a spring in a direction to close the bypass passage,
The bypass valve body is formed into a convex shape having a protruding portion protruding to the opposite side of the bypass passage, and the protruding portion is fitted to the movable cylinder.
Thermo valve device for internal combustion engine.

Images