JPS58199220A - Mounting equipment of power unit - Google Patents

Abstract

PURPOSE:To maintain the posture of a power unit under a certain condition by controlling pressure fluid supplied into two fluid chambers in which a piston divides a cylinder, in accordance with relative displacement between the power unit and a car body. CONSTITUTION:A when a change-over valve 47 is positioned at the neutral position in a normal state oils in fluid chambers 23 and 24 which are formed inside a cylinder 22 of a mounting equipment 21 are trapped therein, respectively, forcing a piston 25 to a locking position in the middle of the cylinder 22. Fine tremor of a power unit transmitted via a bracket 34 travels through a piston rod 26, cylinder 22 and other elements to an insulator rubber 27 and absorbed. On the other hand, if said rubber 27 is deformed at quick acceleration, because the power unit generates an intense torque reaction force a displacement sensor 45 issues an output to a control unit 46, which has the change-over valve 47 shifted to a position II. The piston 25 is thereby pushed up so that a distance between the brackets 32 and 34 may be maintained at a certain value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power unit mounting device for mounting a power unit, in which an engine and a transmissive switch are integrally combined, to a vehicle body in a vibration-proof manner.

As a conventional power unit mounting device,
For example, there are those shown in FIGS. 1 to 6.

In FIGS. 1 to 3, reference numeral 1 denotes a horizontal power unit arranged so that the engine crankshaft extends in the lateral direction of the vehicle body. This power unit 1 has an insulator rubber 2 having a substantially rectangular parallelepiped shape as shown in FIG. 12 mounting device 5 which has an insulator rubber 4 and attaches the left front upper part of the power unit 1 to the vehicle body, and a 1@3 mounting device 6 which also has an insulator rubber 4 and attaches the right front upper part of the power unit 1 to the vehicle body. , and has substantially cylindrical insulator rubbers 7.8 at both ends of the rod 9 as shown in FIG. 6, and attaches the front lower part of the power unit 1 to the vehicle body. , a fifth mounting device 11 that also has an insulator rubber 7.8 and a rod 9 and attaches the rear center portion of the power unit 1 to the vehicle body.
The torque reaction force is mainly supported by the and, and it can be attached to the vehicle body.

However, such a conventional mounting device 3
．． 5.6.10.11, the amount of displacement of the mounting device 3.5.6.1O111, that is, the amount of deformation of the insulator rubber 2.4.7.8, is the amount of displacement of the mounting device 3.5.6.1O111. Since the force applied to the mounting device 3.5.6.10.11 is approximately proportional to the force applied to the mounting device 3.5.6.10.11, if an excessive input is applied such as a torque reaction force during sudden acceleration or engine braking, or a load during vehicle body balancing, the mounting device 3.5.6.10.11
There is a risk that the power unit 1 will be displaced significantly, causing the power unit 1 to tilt, and may interfere with other parts in the engine room or the vehicle body. In order to prevent this, conventionally, the insulator rubber 2.4 of the mounting device 3.5.6.10.11
．． By increasing the spring constant of 7.8 from the beginning, it is difficult to displace the mounting devices 3.5.6.1o, 11, or by providing a stopper structure, the mounting devices 3.5.6.10.11 The position of displacement was kept below a certain value.

However, as mentioned above, the mounting device 3.5
．． 6.10.11 Insulator Rubber 2.4.7.
If the spring constant of 8 is increased, the vibration of the power unit 1 will be easily transmitted to the vehicle body, and the sound and vibration characteristics inside the vehicle will deteriorate. In addition, in the case of a device equipped with a stopper structure, when the mounting device 13.5.6.1O111 comes into contact with the cast bar, the spring constant of the mounting device 3.5.6, 10111 becomes similarly high. ,
Similarly, there was the problem that vibrations were more easily transmitted to the car body, worsening the sound and vibration characteristics inside the car.

The present invention was made by focusing on such conventional problems, and includes a cylinder having two fluid chambers defined by a piston inside, a piston rod connected to the piston, and a cylinder having two fluid chambers defined by a piston. a pressure fluid control means for supplying or discharging pressure fluid to the cylinder or the piston rod; and an elastic body fixed to either the cylinder or the piston rod. It is an object of the present invention to solve the above-mentioned problems by providing a mounting device in which either the power unit or the vehicle body is attached to either the power unit or the vehicle body.

The present invention will be explained below based on the drawings.

7 to 9 show an embodiment of the present invention.

First, the configuration will be explained. In Figures 7 and 8,
Reference numeral 21 generally indicates a mounting device for the power unit throat. This mounting device 21 is, for example, a first
It is provided at the positions of the conventional fourth and fifth mounting devices 10 and 11 shown in the figures through FIG. 3, and mainly supports the torque reaction force of the power unit. Mounting device 21
The cylinder 22 is made of a rigid material such as metal, and the cylinder 22 is slidably housed inside the cylinder 22.
The piston 5 has a rigid piston 5 made of metal or the like defining two fluid chambers 23 and 24, and a piston rod also made of rigid metal or the like connected to the piston 25 and protruding from the upper end of the cylinder 22. Here, the axial directions of the piston rod 26 and the cylinder 22 face the same direction as the axial direction of the rod 9 of the conventional mounting devices 10 and 11, that is, the same direction as the load direction due to the torque reaction force of the power unit. The inner circumferential side of an annular insulator rubber 27 as an elastic body is fixed to the outer circumferential side of the cylinder n, and the outer circumferential side of the insulator rubber 27 is fixed to the inner circumferential side of a cylindrical member. A flange portion 29 is welded to the outer side of the lower end of the cylindrical member 4, and the flange portion is fastened to a vehicle body side bracket 32 with bolts 30 and nuts 31. Note that the shearing direction of the insulator rubber 27 substantially coincides with the axial direction of the piston rod. The diameter of the protruding upper end of the piston rod is reduced to form a step, and a screw 33 is provided above the step. A power unit side bracket 34 is attached to that stepped portion of the piston rod, and is fastened with a nut 35 and a washer. An oil passage 37 is provided inside the piston rod, and communicates between the fluid chambers above the cylinder 22 and the upper end of the screw thread. A protrusion 39 is provided at the bottom of the cylinder 22 in which an oil passage blade is formed that communicates with the lower and upper fluid chambers. Reference numeral 40 designates an annular lid forming the upper end wall of the cylinder 22, which inserts the seal 41 and is screwed onto the upper end of the cylinder n. 42 is! 40, a seal 43 is provided in the center, and the piston rod 26 is inserted therethrough in a fluid-tight manner. 44 is a pressure fluid control means, and the cylinder 22
Pressure oil is supplied or discharged between the fluid chambers of U. The pressure fluid control means 44 includes a displacement sensor 45, such as a potentiometer, provided between the vehicle body side platen 32 and the power unit side bracket. Both ends of the displacement sensor 45 are rotatably attached to both brackets 32 and 34, and the displacement sensor 45 measures the amount of relative displacement between the vehicle body side bracket 32 and the power unit side bracket 34, that is, the distance between the power unit and the vehicle body. The relative displacement amount is detected and input to the control unit 46. Reference numeral 47 denotes a three-position electromagnetic switching valve, which is switched to three positions 11 (2) and (2) by a control unit 46. This switching valve 47 is connected to a supply path 48 through which pressure oil is supplied from a hydraulic pump (not shown) and a drain path 49 that communicates with a reservoir tank (not shown). In addition, the switching valve 4
7 has an oil passage 37.3 between the fluid chambers of the cylinder 22, and 24 has an oil passage 37.3.
The oil passages 51 that communicate via 8 are connected.

Next, the effect will be explained. In this mounting device 21, when the distance between the power unit (not shown) and the vehicle body (not shown) detected by the displacement sensor 45 is close to a predetermined distance, the φ switching valve 47 is placed at the neutral position (2), and the fluid chambers 23, 24 The oil is confined within the fluid chamber 24 and fixes the piston 5 in the central position of the cylinder 22. The small amplitude vibration of the power unit (not shown) is caused by the piston rod 26, piston 5,
It is transmitted to the insulator rubber 27 via the cylinder 22. Since this vibration acts in the shearing direction of the insulator rubber 27, the spring constant of the insulator rubber 27 is small. Therefore, the insulator rubber 27 absorbs vibrations of the power unit well, prevents them from being transmitted to the vehicle body, and prevents muffled noise from occurring.

Next, when the power unit (not shown) generates a large torque reaction force, for example during sudden acceleration, the insulator rubber 27 of the mounting device 21 acts on this torque reaction via the piston rod A, the piston 5, and the cylinder 22. A large shearing deformation occurs when a force (downward force in FIG. 8) is applied in the shearing direction. In this way, the insulator rubber nail is deformed and the power unit side bracket 3
4 approaches the vehicle body side bracket wing within a certain distance,
Upon receiving the signal from the displacement sensor 45, the control unit 46 switches the switching valve 47 from the neutral position ■ to the position ■, supplies pressure oil to the fluid chamber 24 below the cylinder 22, and supplies the fluid above the cylinder 22. Drain the oil between the rooms. Therefore, the piston rises relative to the cylinder 22 due to the differential pressure between the fluid chambers 24, pushes up the power unit side bracket 34 via the piston rod, and pushes up the power unit side bracket 34 and the vehicle body side bracket 34. Adjust so that they are at the specified interval.

0 On the other hand, when a power unit (not shown) generates a large torque reaction force in the opposite direction, for example during engine braking, the insulator rubber nail of the mounting device 21 absorbs this torque reaction force (in FIG. 8) in the opposite direction. Similarly, a large shear deformation occurs when an upward force is applied in the shear direction.

In this way, when the power unit side bracket 34 separates from the vehicle body side bracket 32 by a certain distance or more, the control unit 46 receives a signal from the displacement sensor 45 and switches the switching valve 47 from the neutral position I to the position ■. Pressure oil is supplied between the upper fluid chambers of the cylinder 22, and oil in the lower fluid chamber 24 is discharged. The piston moves downward relative to the cylinder 22 due to the differential pressure between the fluid chamber 23 and the air, and pushes down the power unit side bracket through the piston rod, causing the power unit side bracket and the vehicle body side bracket 32 to move downward. Adjust to achieve the specified spacing.

As a result, as described above, even if a large force is input to the mounting device 221 and the insulator rubber 1-27 undergoes a large shear deformation, the mounting device 21 is not stopped by the stopper structure, so the insulator rubber The part of the nail with a low spring constant in the shearing direction absorbs the vibration of the power unit and blocks its transmission to the car body, improving the soundproofing and vibration-proofing properties of the car interior. Furthermore, when the insulator rubber 27 undergoes large shearing deformation due to receiving a large input as described above, the cylinder 22
Hydraulic pressure is supplied between the fluid chambers of , and inside U to suppress the movement of the power unit (not shown), so the posture of the power unit can be maintained even without a stopper, and interference between the power unit and other parts in the engine room can be prevented. I can do it.

FIG. 9 is a graph showing the characteristics of the mounting device 21 of this embodiment in comparison with the characteristics of the conventional mounting devices 1o, ]1, in which the horizontal axis represents the amount of displacement of the insulator rubber of the mounting device, and the vertical axis 2 The 0 curve A that shows the force shows the characteristics of the conventional mounting device 10.11. Since the displacement is suppressed by δS by the stopper, the curve A suddenly rises in the vicinity. ing. Therefore, the spring constant expressed by the slope of curve A becomes thicker as the force increases.

On the other hand, the straight line B shows the characteristics of the mounting device 21 of this embodiment, and since the mounting device 21 of this embodiment does not have a stopper, it has an approximately constant spring constant. Therefore, if the same force F is applied to the conventional mounting device 10.11 and the mounting device 21 of this embodiment, the conventional mounting device will have a larger spring constant and will be displaced by δ8. On the other hand, since the mounting device 21 of this embodiment does not have a stopper and undergoes shearing deformation, the spring constant is small and the mounting device 21 is displaced by δB, which is larger than δ^. By the way, the displacement δB of the mounting device 21 of this embodiment is canceled by the movement of the piston rod 26, so even without a stopper, the movement of the power unit will be about the same as the displacement δA of the conventional mounting device, and the power unit nod. Interference with other parts is prevented. Moreover, since the spring constant of the mounting device 21 is small, it is possible to absorb vibrations of the power unit well and prevent transmission to the vehicle body, thereby providing excellent soundproofing and vibrationproofing performance.

[In the above description, the mounting device 21
．． Conventional fourth and fifth mounting devices 1 shown in Figure 2
3.5.6 Other conventional first, second, and third mounting devices are described as being mounted at the O111 position.
It may be installed in the position of Further, in the above-described embodiment, the displacement sensor 45 detects the relative distance between the power unit and the vehicle body, but it may also detect the force acting between the power unit and the vehicle body.

FIG. 10 shows a second embodiment of the invention.

In this embodiment, piston rods 26 and 524 are attached to the upper and lower surfaces of the piston 5, respectively, so that the absolute values of the volume changes between the fluid chambers 24 due to the movement of the piston 25 are equal. , 52 are formed with oil passages 37 and vanes communicating with each fluid chamber 23, 24.

In the mounting device 21 of this embodiment, between the fluid chambers,
24 can be connected to control the fluid pressure between the fluid chambers in a closed system. Other parts that are the same as those in the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 11 shows a third embodiment of the invention.

In this embodiment, a hole is provided in the bottom wall of the cylinder 22, and one end of the bellows is fixed in a liquid-tight manner. The other end of the bellows 54 is fluid-tightly fastened to the lower end surface of the piston 5 with a nut 56, with the seal 5 in between. The inside of the bellows 54 is open to the public. In the mounting device 21 of this embodiment, by appropriately selecting the diameter of the piston rod 26 and the effective cross-sectional area of the bellows, the upper and lower fluids due to the movement of the piston 6 can be The absolute value of the volume change amount between the rooms and 24 can be made the same. Other parts that are the same as those in the first embodiment are designated by the same reference numerals 5 and their explanations will be omitted.

FIG. 12 shows a fourth embodiment of the invention.

In this embodiment, a cylindrical rubber bush 57 is attached to the lower end of the cylinder 22.

5 is a piston, 1 is a piston rod, 24 is a fluid chamber.

In addition, in the above-mentioned 2.3.4 embodiments, the pressure fluid control means was omitted for convenience of explanation, but it goes without saying that all the embodiments have the pressure fluid control means.

As described above, according to the present invention, there is provided a cylinder having two fluid chambers defined therein by a slidable piston, a piston rod connected to the piston and protruding from the cylinder, and a power unit. A pressure fluid control means that detects the relative displacement with respect to the vehicle body or the force acting between the power unit and the vehicle body and supplies pressure fluid to or discharges the fluid from the two fluid chambers of the cylinder, and either the cylinder or the piston rod. 6. Attach the elastic body to either the power unit or the vehicle body, attach the other of the cylinder or piston mouth/nod to the power unit or the vehicle body, and attach the elastic body to either the power unit or the vehicle body. When the deformation of the body becomes large and the amount of relative displacement of the power unit with respect to the vehicle body reaches a predetermined value or more, the pressure fluid control means supplies or discharges pressure fluid to the fluid chamber of the cylinder so as to reduce this relative displacement position. Because of that,
It is possible to lower the spring constant of the elastic body and eliminate the need for a stopper. Therefore, the posture of the power unit can be maintained, and vibrations of the power unit can be prevented from being transmitted to the vehicle body, resulting in excellent soundproofing and vibration-proofing properties in the vehicle interior. Furthermore, if the load is applied in the shearing direction of the elastic body, the spring constant can be further reduced.

In addition, in this invention, the rigid cylinder and piston provide a position control function, and the elastic body provides a vibration damping function, so that the respective functions are separated.
Even if the spring constant 7 of the elastic body is small, there is an effect that the responsiveness of the cylinder position control function can be improved.

[Brief explanation of the drawing]

IFII is a plan view showing a conventional power unit mounting device together with the power unit, FIG. 2 is a side view showing the conventional power unit mounting device together with the power unit, and FIG. 3 is a front view showing the conventional power unit mounting device together with the power unit. 4 to 6 are sectional views of a conventional power unit mounting device, FIG. 7 is a perspective view of a power unit mounting device according to a first embodiment of the present invention, and FIG. 8 is a power unit mounting device according to this embodiment. FIG. 9 is a graph showing a comparison of the characteristics of the power unit mounting device of this embodiment with the characteristics of a conventional power unit mounting device, and FIG. FIG. 11 is a sectional view of a mounting device for a power unit according to a third embodiment of the present invention.
FIG. 2 is a sectional view of a power unit mounting device according to a fourth embodiment of the present invention. 21---Power unit mounting device,
22-m-cylinder, edict, 24----fluid chamber, 25
--- Piston, 26--- Piston Rondo,
27・----1・Insulator rubber, 32---
・Bracket on vehicle body side, 34-------Bracket on power unit side, 44-
...-Pressure fluid control means, 45--Displacement sensor, 46--Control unit, 47--Three position electromagnetic switching valve, 48--One supply path, 49-- drain path. Patent Applicant Nissan Motor Co., Ltd. Patent Attorney Gigagun Part 4 Figure 5 g To Figure 11 Figure 1 Dimension l 1-2 1 "■ ♂ ?? = 4

Claims (2)

[Claims] (1) A cylinder in which two fluid chambers are defined inside by a movable piston, a piston rod connected to the piston and protruding from the cylinder and facing the load direction, and a connection between the power unit and the vehicle body. pressure fluid control means that detects relative displacement or force acting between the power unit and the vehicle body and supplies pressure fluid to two fluid chambers of the cylinder or discharges fluid from the fluid chambers; and the cylinder or the piston rod. an elastic body fixed to either one of the power unit or the vehicle body, and the elastic body is attached to either the power unit or the vehicle body, and the other of the cylinder or the piston rod is attached to the other of the power unit or the vehicle body. When the deformation of the elastic body becomes large and the amount of relative displacement of the power unit with respect to the vehicle body reaches a predetermined value or more, the pressure fluid control means supplies pressure fluid to the fluid chamber of the cylinder so as to reduce the amount of relative displacement. A power unit mounting device characterized by supplying or discharging. (2) The power unit mounting device according to claim 1, wherein the direction of shear deformation of the elastic body is substantially the same as the axial direction of the piston rod.