JPH0655082U - Heat exchanger with bypass valve - Google Patents

Abstract

(57) [Abstract] [Purpose] By automatically maintaining the pressure loss in the heat exchanger below a prescribed value even if the oil amount or oil temperature (or oil viscosity) at the heat exchanger inlet changes. Provide a small heat exchanger with improved cooling efficiency. [Structure] Hydraulic clutch 2 with variable degree of coupling
And a hydraulic pump 13 driven by an input side member of the hydraulic clutch 2, and the pressure oil discharged from the hydraulic pump is transferred to the heat exchanger 2
In the power transmission device that supplies oil to the lubricating oil line 26 via 5, the bypass oil passage 20 is installed in parallel with the heat exchanger 25, and the bypass valve 17 is provided in the middle of the oil passage. The bypass valve 17 opens when the pressure loss in the heat exchanger 25 exceeds a predetermined value, and has a function of bypassing a part of the pressure oil from the upstream side to the downstream side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to miniaturization of a heat exchanger used in a power transmission device, and more particularly to a heat exchanger having a bypass valve installed in a bypass oil passage.

[0002]

[Prior art]

 A power transmission device for a ship that transmits the output of the main engine to a propeller through a hydraulic clutch, which is required by slip-controlling the hydraulic clutch while the engine is fixed at an idle speed when traveling at a very low speed. Gaining speed has been a traditional practice. FIG. 4 shows the amount of lubricating oil required for a marine propulsion device that has been conventionally implemented and directly controls or slip-controls a hydraulic clutch, and the hydraulic pump discharge amount driven by a main engine.

Since the calorific value of the hydraulic clutch associated with the slip operation during the slow speed navigation is significantly larger than that during the direct drive operation, it is necessary to remove the heat generation as shown by the line segment A in FIG. The amount of lubricating oil is larger than that in the direct operation range.

Further, from the viewpoint of space saving and energy saving, it is widely known that the hydraulic pump for supplying the lubricating oil is driven from an input member of a hydraulic clutch connected to the engine through a gear, and the discharge thereof. The amount is set so that the maximum amount of lubricating oil required at the time of slip operation can be obtained at the engine idle speed, so as shown by line B in Fig. 4, it is proportional to the engine speed in the direct drive range. A certain amount of pressure oil is supplied.

On the other hand, since there is no slip heat generation in the hydraulic clutch in the direct connection operation range, the oil circulating in the hydraulic circuit has a low temperature and a high viscosity as compared with during the slip operation. Therefore, when selecting a heat exchanger for a power transmission device in which the oil amount and oil temperature fluctuate depending on operating conditions as described above, the discharge amount of the hydraulic pump is maximized, and high viscosity oil with a relatively low oil temperature is distributed. It was necessary to equip a large heat exchanger so that the oil flow resistance value in the heat exchanger would not exceed the allowable limit even at the engine rated speed.

[0006]

[Problems to be solved by the device]

 As described above, increasing the size of the heat exchanger is expensive, and not only the installation space for the heat exchanger but also the disassembly space for maintenance needs to be wide, especially in the engine room of a ship. There was a problem that the installation of other equipment would be adversely affected in the limited space.

The present invention has been made to solve such a problem, and even if the inlet oil amount or oil temperature (or viscosity) of the heat exchanger changes depending on the operating conditions of the driven machine, the heat exchange is performed. It is an object of the present invention to provide a compact heat exchanger with improved cooling efficiency by automatically maintaining the pressure loss inside the unit below a predetermined value.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention comprises a hydraulic clutch whose coupling degree is variably adjustable, and a hydraulic pump which is connected to an input side member of the hydraulic clutch via a gear. In the power transmission device that adjusts the pressure oil of the above to a predetermined pressure by the hydraulic pressure adjusting valve and supplies it to the hydraulic clutch, and also supplies the oil discharged from the hydraulic pressure adjusting valve to the lubricating oil line via the heat exchanger, A bypass oil passage that directly connects the oil inlet and oil outlet of the heat exchanger is provided in parallel with the heat exchanger, and only if the pressure loss in the heat exchanger exceeds a specified value in the bypass oil passage, the upstream This is achieved by installing a bypass valve that allows the flow of pressure oil from the downstream side to the downstream side.

[0009]

[Action]

 A bypass oil passage was installed in parallel with the heat exchanger, and a bypass valve was installed in the middle of the heat exchanger.Therefore, pressure loss in the heat exchanger due to increase in hydraulic pump discharge, viscosity increase due to oil temperature decrease, etc. When the above is reached, the bypass valve opens and part of the pressure oil does not pass through the heat exchanger but flows directly into the lubricating oil line, and the pressure loss inside the heat exchanger is automatically maintained below the specified value. .

As a result, the pressure loss becomes smaller than in the case of the conventional technique, and the number of baffle plates in the heat exchanger is increased accordingly, and even if the oil flow resistance increases, the pressure loss in the conventional technique is consequently increased. The cooling efficiency increases as much as the number of baffle plates stays inside. Therefore, if the amount of heat exchanged and the maximum oil temperature at the outlet of the heat exchanger are the same as in the conventional case, the cooling area of the heat exchanger can be reduced as much as the cooling efficiency is increased, and the size can be reduced.

[0011]

【Example】

 Hereinafter, a heat exchanger with a bypass valve used in a marine propulsion device will be described as an embodiment of the present invention. 1 is a system diagram thereof, and FIG. 2 is a sectional view of a differential pressure valve showing an example of a specific structure of the bypass valve of FIG.

In FIG. 1, an input shaft 3 of a power transmission device connected to a main engine 1 is provided with a hydraulic clutch 2 that also functions as a slipping clutch. This hydraulic clutch 2 itself is, as is well known, an input shaft. 3 and a plurality of input side clutch plates 4 spline-engaged with a clutch carrier 7 and a spline 6 of a clutch hub 33 integrated with a clutch output side pinion 29 and an input-side clutch plate 4. It is composed of a large number of output side clutch plates 5 arranged alternately.

These input / output side clutch plates 4 and 5 are annularly pumped with pressure oil via a clutch switching valve 19 and a hydraulic control valve 21 by a hydraulic pump 13 driven by an input shaft 3 via gears 14 and 15. It is connected by supplying it to the piston chamber 9 and pressing the clutch piston 8. In this case, the degree of engagement of the hydraulic clutch 2, that is, the slip between the input and output side clutch plates 4 and 5 is controlled by arbitrarily changing the hydraulic pressure with the hydraulic control valve 21. When the control pressure of the hydraulic control valve 21 exceeds the set value, the hydraulic clutch 2 switches from slip operation to direct connection operation.

The pinion 29 arranged on the output side of the hydraulic clutch 2 is rotatably supported by the input shaft 3 and meshes with a large gear 34 integrated with the output shaft 30 so that the hydraulic clutch 2 can be connected. Thus, the output of the engine 1 is transmitted to the propeller 32 via the propulsion shaft 31.

On the other hand, the pressure oil from the hydraulic pump 13 is branched from the inlet line 16 of the clutch switching valve 19 and adjusted to the clutch operating oil pressure by the clutch oil pressure adjusting valve 18, and at the same time, the oil pressure of the oil pressure adjusting valve 18 is changed. The discharged oil is cooled by passing through the heat exchanger 25, adjusted to a predetermined lubricating oil pressure by the lubricating oil pressure adjusting valve 24, and passed through the lubricating oil line 26 to the hydraulic clutch 2, the gears 29, 34. Etc.

Now, in the present invention, the bypass oil passage 20 that directly connects the oil inlet 22 and the oil outlet 23 of the heat exchanger 25 is arranged in parallel with the heat exchanger 25, and the bypass oil passage is in the middle. In addition, only when the pressure difference between the oil inlet 22 and the oil outlet 23 caused by the oil flow resistance in the heat exchanger exceeds a predetermined value (for example, 0.5 to 1.0 kg / cm ² ) from the upstream side to the downstream side. The bypass valve 17 that allows the flow of pressure oil is provided.

As an example of a specific structure of the bypass valve 17, a differential pressure valve 46 as shown in FIG. 2 is used. In the differential pressure valve 46, an inlet port 40 is formed in the center of the casing 43, and an outlet port 44 is formed in the direction perpendicular to the inlet port 40. The inlet port 40 and the outlet port 44 are partitioned by a piston 42, and the piston 42 is pressed against the step 41 of the inlet port by a coil spring 45. Further, the spring chamber 48 and the outlet port 44 communicate with each other through an oil passage 47.

With the differential pressure valve 46 installed in the bypass oil passage 20 as the bypass valve 17, the oil flow resistance in the heat exchanger 25 increases, and the pressure difference between the oil inlet 22 and the oil outlet 23 increases. When it rises above the value set by the coil spring 45 of 46, the piston 42 is pushed to the left in the figure, the inlet port 40 and the outlet port 44 communicate, and part of the pressure oil at the heat exchanger inlet bypass oil passage. It passes through 20 and flows directly to the lubricating oil line 26. On the contrary, when the pressure difference falls below the set value, the piston 42 of the differential pressure valve 46 is completely closed and the entire amount passes through the heat exchanger 25. As described above, by installing the bypass valve 17, the pressure loss in the heat exchanger 25 is automatically maintained at a predetermined value or less.

In the above embodiment, the differential pressure valve 46 shown in FIG. 2 is used as the specific structure of the bypass valve, but the bypass valve is not limited to this, and a commercially available check valve 56 shown in FIG. 3 may be used. The same action and effect can be obtained.

That is, the check valve 56 of FIG. 3 pushes open the check valve 54 against the reaction force of the coil spring 55 when the pressure of the inlet port 51 bored in the casing 53 reaches a predetermined value, and opens the inlet. The pressure oil of the port 51 passes through the hole 57 of the check valve 54 and communicates with the outlet port 52, and the pressure of the outlet port 52 also acts as a reaction force of the check valve 54.

[0021]

[Consideration of device]

 According to this invention, when the oil flow resistance in the heat exchanger increases and exceeds the set value, the bypass valve opens and the pressure loss in the heat exchanger is automatically maintained below the set pressure. Compared to the case without bypassing, the number of baffle plates in the heat exchanger can be increased to improve cooling efficiency, and the heat exchanger can be downsized, so that a narrow space such as an engine room can be effectively used. .

[Brief description of drawings]

FIG. 1 is a system diagram of a heat exchanger with a bypass valve used in a marine propulsion device, showing an embodiment of the present invention.

2 is a sectional view of a differential pressure valve showing an example of a specific structure of the bypass valve of FIG.

FIG. 3 is a cross-sectional view of a check valve showing another specific structure of the bypass valve of FIG.

FIG. 4 is a diagram showing a necessary lubricating oil amount of a marine propulsion device which is conventionally implemented and directly controls or slips a hydraulic clutch, and a hydraulic pump discharge amount driven by a main engine.

[Explanation of symbols]

 1 Main Engine 2 Hydraulic Clutch 3 Input Shaft 4 Input Side Clutch Plate 5 Output Side Clutch Plate 6 Spline 7 Clutch Carrier 8 Clutch Piston 9 Piston Chamber 13 Hydraulic Pump 14, 15 Gear 16 Inlet Line 17 Bypass Valve 18 Clutch Hydraulic Pressure Regulator 19 Clutch Switching valve 20 Bypass oil passage 21 Hydraulic control valve 22 Oil inlet 23 Oil outlet 24 Lubricating oil pressure adjusting valve 25 Heat exchanger 26 Lubricating oil line 29 Pinion 30 Output shaft 31 Propulsion shaft 32 Propeller 33 Clutch hub 34 Large gear 40, 51 Inlet port 41 step 42 piston 43, 53 casing 44, 52 outlet port 45, 55 coil spring 46 differential pressure valve 47 oil passage 48 spring chamber 54 check valve 56 check valve 57 hole

Claims (2)

[Scope of utility model registration request] 1. A hydraulic clutch (2) capable of variably adjusting the degree of coupling, and a hydraulic pump (13) connected to an input side member of the hydraulic clutch (2) via gears (14, 15).
And a hydraulic pressure adjusting valve (18) for supplying pressure oil from the hydraulic pump.
A power transmission device that adjusts the pressure to a predetermined pressure with a hydraulic clutch (2) and supplies the oil discharged from the hydraulic pressure regulating valve (18) to a lubricating oil line (26) via a heat exchanger (25). In the above, a bypass oil passage (20) is provided in parallel with the heat exchanger (25) to directly communicate the oil inlet (22) and the oil outlet (23) of the heat exchanger (25), and heat is introduced into the bypass oil passage. A heat exchanger with a bypass valve, characterized in that a bypass valve (17) which allows the flow of pressure oil from the upstream side to the downstream side is installed only when the pressure loss in the exchanger (25) exceeds a predetermined value. . 2. The heat exchanger with a bypass valve according to claim 1, wherein a check valve is provided as the bypass valve.