JP4740064B2 - Oil cooler - Google Patents

Description

  The present invention relates to a plate stack type oil cooler used for cooling oil such as lubricating oil for an internal combustion engine and hydraulic oil for an automatic transmission.

As described in Patent Document 1, for example, as an oil cooler for cooling oil such as lubricating oil of an internal combustion engine or hydraulic oil of an automatic transmission, a large number of core plates are stacked to form an oil flow path and a cooling water flow. There is known a plate-laminated water-cooled oil cooler in which roads are alternately configured.
JP 2002-332818 A

  The technical problem of the present invention will be described with reference to the oil cooler of the comparative example shown in FIGS. The oil cooler 10 includes a core portion 11 in which a plurality of core plates 12 are stacked in the stacking direction, and oil flow paths 13 and cooling water flow paths 14 are alternately formed between adjacent core plates 12. And a base plate 15 that is thicker than the core plate 12, and this base plate 15 is fixed to a cylinder block or the like of the internal combustion engine using bolts. On the outer peripheral portion of each core plate 12 is formed a rising flange portion 16 that is inclined outward (radially outward) and rises upward (upward in FIG. 9) away from the base plate 15 in the stacking direction. An outer peripheral wall portion 17 of the core portion 11 is formed by overlapping the rising flange portion 16. As described above, in the oil cooler 10, the core plate 12 defining the flow paths 13 and 14 also functions as an outer body of the core portion 11, that is, a housing.

  In such a plate laminate type oil cooler 10, the outer peripheral wall portion 17 of the core portion 11 has a lowermost layer portion 17A formed only by the rising flange portion 16 of the lower plate 12A, and a plurality of cores. There is a general portion 17B where the rising flange portion 16 of the plate 12 overlaps. Accordingly, the thickness (diameter dimension) of the lowermost layer portion 17A is only one of the rising flange portions 16, and the structure is locally thin and fragile as compared with the other general portions 17B.

  Further, in order to ensure a sufficient flow rate of the oil to be cooled, generally, as shown in FIG. 1 of the above Japanese Patent Laid-Open No. 2002-332818, the lower plate 12A and the upper core plate 12 The lowermost flow path 18 formed between the two is the oil flow path 13. For this reason, one of the upper and lower surfaces of the intermediate plate 12B excluding the lower plate 12A (and the uppermost core plate) in the core plate 12 faces (contacts) the cooling water flow path 14. On the other hand, only the lower plate 12 </ b> A does not face the cooling water flow path 14. Therefore, when the cooling water suddenly flows into the cooling water flow path 14 while high-temperature oil is flowing through the oil flow path 13, many intermediate plates 12B facing the cooling water flow path 14 contract due to thermal contraction. Since it is pulled and deformed in the direction F1 (see FIG. 10), only the upper side of the lowermost layer portion 17A is drawn inward in the radial direction as exaggeratedly drawn in FIG. 10B. Since distortion and deformation occur and stress concentration easily occurs, and the lowermost layer portion 17A is thinner and more fragile than the other general portions 17B, it is very important to ensure its reliability and durability. Have difficulty.

  The present invention has been made in view of the technical problem peculiar to such an oil cooler, and is the lowermost layer portion formed only by the rising flange portion of the lower plate in the outer peripheral wall portion of the core portion. The purpose is to reduce or avoid the occurrence of distortion, deformation and stress concentration, and to improve its reliability and durability.

  The oil cooler according to the present invention forms a core portion in which a plurality of core plates are stacked in the stacking direction, and an oil flow path and a cooling water flow path are alternately formed between adjacent core plates, and a bottom surface of the core section. The base plate is fixed to the lower plate and thicker than the core plate, and the outer peripheral portion of each core plate stands up while being inclined outwardly away from the base plate in the stacking direction. An upper flange portion is formed, and the rising flange portions of a plurality of core plates are overlapped to form an outer peripheral wall portion of the core portion, and on this outer peripheral wall portion, a lowermost layer portion formed only by the lower plate and A general portion where the rising flange portions of the plurality of core plates overlap.

In the present invention, the lowermost flow path formed between the lower plate and the upper core plate is defined as an oil flow path, and below the lowermost oil flow path with the lower plate interposed therebetween. The auxiliary cooling water flow path through which the cooling water flows along the lower plate is recessed in the base plate, and the lower plate is positioned between the lowermost oil flow path and the auxiliary cooling water flow path. It is configured to do.

According to this invention, is a technical problem specific to oil cooler plate laminate type described above, the lowermost portion formed only by the rising flange portion of the lower plate in the outer peripheral wall portion of the core portion Strain / deformation and stress concentration can be reduced and avoided, and its reliability and durability can be improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that components that are substantially the same as those in the comparative example are given the same reference numerals.

  First, a first embodiment of the present invention will be described with reference to FIGS. The oil cooler 10 includes a plurality of core plates 12 stacked in the stacking direction, an oil passage 13 through which engine oil flows between adjacent core plates 12, and a cooling water passage 14 through which engine cooling water flows. And core portions 11 formed alternately in the stacking direction, that is, alternately, and a base plate 15 fixed to the bottom surface of the core portion 11 and thicker than the core plate 12. ing. The base plate 15 is provided with a flange portion 19 projecting laterally from the core portion 11, and a plurality of bolt holes 19 </ b> A are formed through the flange portion 19. The base plate 15 of the oil cooler 10 is fastened together with, for example, a fixing portion (not shown) on the cylinder block side of the engine by fixing bolts (not shown) that pass through these bolt holes 19A.

  On the outer peripheral portion of each core plate 12, a rising flange portion 16 that is inclined outwardly, that is, radially outward and rises upward from the base plate 15 in the stacking direction (upward in FIG. 1) is bent. An outer peripheral wall portion 17 of the core portion 11 is formed by overlapping the rising flange portion 16 without any gap. As described above, the oil cooler 10 has a so-called housingless type plate-stacked structure in which the core plate 12 that defines the flow paths 13 and 14 also functions as an outer body of the core portion, that is, a housing. . A layer of brazing material is formed on the surface of each core plate 12 (and base plate 15), and brazing is performed in a high-temperature furnace with each component temporarily assembled during manufacture. Thus, the parts are joined together by brazing.

  As shown in FIG. 4, the outer peripheral wall portion 17 of the core portion 11 constituting the outer wall of each flow path 13, 14 is formed only by the rising flange portion 16 of the lower plate 12 </ b> A that forms the bottom surface of the core portion 11. There are a lowermost layer portion 17A and a general portion 17B where at least two rising flange portions 16 of the plurality of core plates 12 are superposed. In other words, in the general portion 17B, the length and inclination angle of the rising flange portion 16 are set so that at least two or more rising flange portions 16 overlap in the radial direction. Therefore, when the lower plate 12A is set to the same thickness as the other intermediate plate 12B for the purpose of sharing parts as in the first embodiment, the thickness of the lowermost layer portion 17A is one plate. There is only a minute, and it has a locally thin and fragile structure as compared with the other general part 17B.

  As shown in FIGS. 2 and 3, the core portion 11 includes two oil longitudinal passages 20 that penetrate the inside of the core portion 11 in the stacking direction and communicate with the respective oil passages 13, and an upper portion of the core portion 11. And an oil communication passage 21 (see FIGS. 1 and 2) that connects the two oil longitudinal passages 20 to each other. The engine oil is supplied into the oil passage 13 through the oil longitudinal passage 20 and the oil communication passage 21 and flows through the oil passage 13. The core portion 11 has two cooling water longitudinal passages 22 that penetrate the inside of the core portion 11 in the stacking direction and communicate with the respective cooling water flow paths 14, and each cooling water fixed to the upper surface of the core portion 11. Two cooling water piping parts 23 connected to the vertical passage 22 are provided. The cooling water is supplied from the engine side to each cooling water flow path 14 through one cooling water piping section 23 and the cooling water vertical passage 22, and after flowing through each cooling water flow path 14, the cooling water is cooled with the other cooling water vertical passage 22. It returns to the engine side through the water piping part 23.

  In the first embodiment, as in the comparative example described above, the lowermost flow path 18 formed on the lower plate 12A is connected to the oil flow path 13 in order to sufficiently secure the flow rate of the oil to be cooled. Is done. Further, for the purpose of sharing parts, the lower plate 12A is set to have substantially the same thickness as the other intermediate plate 12B. The base plate 15 is provided with an auxiliary cooling water passage 24 through which cooling water flows, below the oil passage 13 which is the lowermost passage 18 with the lower plate 12A interposed therebetween. In FIG. 3, for the sake of clarity, the area of the auxiliary cooling water flow path 24 is hatched. As shown in FIG. 3, the auxiliary cooling water flow path 24 is similar to each cooling water flow path 14. The cooling water is communicated with the cooling water longitudinal passage 22, and the cooling water is supplied to the auxiliary cooling water passage 24 through the one cooling water longitudinal passage 22, flows through the auxiliary cooling water passage 24, and then the other cooling water. It flows to the longitudinal passage 22. As shown in FIG. 4, the lower plate 12 </ b> A is joined to the upper surface of the base plate 15 remaining at the peripheral edge of the auxiliary cooling water flow path 24.

  According to the first embodiment as described above, the lowermost flow path 18 of the core portion 11 is used as the oil flow path 13, while ensuring a sufficient flow rate of engine oil, the lowermost flow path 18 is lowered below the lowermost flow path 18. Since the auxiliary cooling water channel 24 is formed with the side plate 12A interposed therebetween, the lower surface of the lower plate 12A faces the auxiliary cooling water channel 24 like the other intermediate plates 12B facing the cooling water channel 14. It becomes. Therefore, when the low-temperature cooling water suddenly flows into the cooling water channel 14 while the high-temperature oil is flowing through the oil channel 13, the lower plate 12 </ b> A is also affected by the water temperature in the same manner as the other core plates 12. In order to heat-shrink, the distortion and deformation of the lowermost layer portion 17A of the lower plate 12A that is particularly thin and fragile among the outer peripheral wall portions 17 of the core portion 11 as described above, and the stress concentration resulting therefrom are effective. Can be reduced or eliminated.

  In particular, as in the first embodiment, when the base plate 15 is configured by superposing the upper plate 15A and the lower plate 15B in order to ensure the desired thickness and ensure the strength and rigidity. The above-mentioned auxiliary cooling water flow path 24 can be formed through the upper plate 15A joined to the core portion 11, and the processing operation is easy.

In the reference examples described below, the same reference numerals are assigned to the same components as those in the above-described embodiments, and a duplicate description is omitted as appropriate.

FIG. 5 shows a first reference example. In the first reference example, the base plate 15 has a simple structure in which the auxiliary cooling water flow path (24) is not provided, and the lower plate 12A has the rising flange portion 16 more than the other intermediate plate 12B. It differs from the said 1st Example by the point currently formed thickly. That is, the thickness direction dimension D1 of the lower plate 12A is set larger than the thickness direction dimension D0 of the other intermediate plate 12B. And the radial direction dimension (D1) of the lowermost layer part 17A comprised by the single lower side plate 12A is made into the thickness direction dimension (2) of the other general part 17B comprised by the several core plate 12 overlapping. XD0) or more. As a result, the strength and rigidity of the lowermost layer portion 17A in the outer peripheral wall portion 17 of the core portion 11 can be ensured to be equal to or higher than that of the other general portion 17B, and the distortion, deformation, and stress concentration can be effectively reduced.・ Can be resolved.

FIG. 6 shows a second reference example. In the third embodiment, the lower plate 12A is set to the same thickness as the other intermediate plate 12B, and the auxiliary cooling water passage 24 is not provided as in the first embodiment. In addition, the lowermost flow path 18 formed on the lower plate 12A is a cooling water flow path 14. According to the second reference example, the lower plate 12A also faces the cooling water flow path 14 like the other intermediate plates 12B. Therefore, when the low temperature water suddenly flows in the cooling water flow path 14 while the high temperature oil flows in the oil flow path 13, as shown by the arrow F1, the lower plate 12A also has another intermediate plate 12B. In the same manner as described above, since the heat shrinks due to the influence of the water temperature, as described above, the distortion / deformation and stress concentration of the lowermost layer portion 17A which is particularly thin and fragile among the outer peripheral wall portions 17 of the core portion 11 are effectively reduced.・ Can be resolved.

FIG. 7 shows a third reference example. In the third reference example, similarly to the first reference example, the thickness D1 of the lower plate 12A including the rising flange portion 16 is set to be larger than the thickness D0 of the other intermediate plate 12B, and the second As in the reference example , the lowermost flow path 18 is the cooling water flow path 14. According to such a configuration, the effects of both the first reference example and the second reference example can be obtained, and the distortion / deformation and stress concentration of the lowermost layer portion 17A in the outer peripheral wall portion 17 can be further ensured. It can be reduced or eliminated.

FIG. 8 shows a fourth reference example. In the fourth reference example, the base plate 15 is provided with a recess 25 into which the lower plate 12A is fitted. The inner wall surface of the concave portion 25 and the outer peripheral surface of the rising flange portion 16 of the lower plate 12A face each other substantially without any gap, and are firmly joined to each other by the brazing process described above. According to the fourth reference example, since the lower plate 12A is stably supported by the peripheral wall portion of the concave portion 25 of the base plate 15, the lower plate 12A is thickened as in the first reference example. Similarly, the distortion / deformation of the lowermost layer portion 17A of the lower plate 12A that is particularly thin and fragile among the outer peripheral wall portions 17 of the core portion 11 can be remarkably reduced or eliminated.

As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above embodiments, and includes various modifications and changes without departing from the spirit of the present invention. . For example, in the fourth reference example shown in FIG. 8, the lowermost flow path 18 is used as the oil flow path 13 in order to improve the oil flow rate, but it is the same as the second and third reference examples shown in FIGS. In addition, the lowermost flow path 18 may be used as the cooling water flow path 14 in order to further reduce and eliminate distortion / deformation and stress concentration of the lowermost layer portion 17A.

The side view which shows an example of the oil cooler which concerns on this invention. The top view which shows the said oil cooler. The upper surface corresponding view which shows the base plate of the said oil cooler alone. 1 is a cross-sectional view of a main part showing an oil cooler according to a first embodiment of the present invention. The principal part sectional view showing the oil cooler concerning the 1st reference example. The principal part sectional view showing the oil cooler concerning the 2nd reference example. The principal part sectional drawing which shows the oil cooler which concerns on the 3rd reference example of this invention. The principal part sectional drawing which shows the oil cooler which concerns on the 4th reference example of this invention. The principal part sectional view showing the oil cooler concerning a comparative example. Explanatory drawing which shows the mode of distortion and a deformation | transformation of the oil cooler which concerns on the said comparative example.

DESCRIPTION OF SYMBOLS 10 ... Oil cooler 11 ... Core part 12 ... Core plate 12A ... Lower plate 12B ... Intermediate plate 13 ... Oil flow path 14 ... Cooling water flow path 15 ... Base plate 16 ... Standing flange part 17 ... Outer peripheral wall part 17A ... Bottom layer part 17B ... General part 18 ... Lowermost flow path 24 ... Auxiliary cooling water flow path 25 ... Recess

Claims (1)

A plurality of core plates are laminated in the laminating direction, and fixed to a core part in which oil flow paths and cooling water flow paths are alternately formed between adjacent core plates, and a lower plate that forms the bottom surface of the core part, A base plate thicker than the core plate,
On the outer peripheral portion of each core plate, a rising flange portion that rises while being inclined outward and spaced apart from the base plate in the stacking direction is formed, and the core portions are formed by overlapping the rising flange portions of the plurality of core plates. An outer peripheral wall portion is formed,
In this outer peripheral wall portion, an oil cooler provided with a lowermost layer portion formed only by the rising flange portion of the lower plate and a general portion where the rising flange portions of a plurality of core plates overlap,
The lowermost flow path formed between the lower plate and the upper core plate is an oil flow path,
In addition, an auxiliary cooling water flow path through which the cooling water flows along the lower plate is recessed in the base plate below the lowermost oil flow path across the lower plate so that the lowermost oil flow is An oil cooler characterized in that the lower plate is positioned between a passage and the auxiliary cooling water passage .

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