JPH02197471A - Mounting device for cab - Google Patents

Abstract

PURPOSE:To allow a leveling function to be added by inserting a hydraulic stabilizer, consisting of a pair of hydraulic cylinders suppressing pitching of a cab, to be interposed between a car body frame and the cab and connecting a hydraulic pressure source through a selector valve to chambers mutually in an opposite side in both the hydraulic cylinders. CONSTITUTION:In the case of a truck mounting to a front end part of a frame constituting a body of the truck a cab 11 through a cab suspension device consisting of front and rear suspension springs 12, 13, a hydraulic stabilizer, comprising front and rear hydraulic cylinders 15, 16, is mounted interposing between the body frame 10 and the cab 11. The front and rear hydraulic cylinders 15, 16 are connected in a manner wherein a chamber mutually in an opposite side for a piston communicates by communication pipes 19, 20. The communication pipes 19, 20 are connected respectively to accumulators 21, 22 each connected to a selector valve 23 controlling pressure oil supplied and discharged, and the selector valve 23 is controlled in its rotary position by a microcomputer 24.

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a cab mounting device, and more particularly to a device for mounting a cab on a vehicle body frame via a cab suspension device.

[Summary of the invention 1] A hydraulic stabilizer for suppressing pitching or rolling of the cab is interposed between the cab mounted via a cab suspension device and the vehicle body frame, and a hydraulic source is connected via a switching valve. This device is connected to chambers on opposite sides of a pair of hydraulic cylinders that make up the hydraulic stabilizer, and this adds a leveling function to the hydraulic stabilizer, allowing the cab to return to its normal position if it is tilted. It was designed so that 2. Description of the Related Art In general, a truck has a cab mounted on the front end of its body frame. Since hard springs that can withstand high loads are used as suspension springs to suspend the axle, if the cab is mounted directly on the frame, vibrations will be transmitted to the cab through the suspension springs and the frame, resulting in poor ride comfort. Deteriorate. Therefore, the cab is mounted on the frame via a suspension spring, which absorbs vibrations and improves riding comfort. 1. Problems to be Solved by the Invention] However, the cab suspension device has a high center of gravity even though the distance between the front and rear suspension springs is short, and the stroke of the suspension spring is also smaller than that of a passenger car. Therefore, pitching tends to occur when the vehicle suddenly starts or brakes, and rolling occurs when the vehicle turns. Such pitching and rolling can affect the stroke of the suspension spring, causing bottoming, which worsens the ride comfort of the cab. In order to improve the deterioration in riding comfort caused by such pitching and rolling, it is considered to increase the spring constant and damping force of the cab suspension spring to reduce the movement of the cab. However, such measures limit the effectiveness of the cab suspension device, leading to deterioration in ride comfort. Improvements through suspension geometry such as anti-nose dive geometry and anti-roll geometry are also being considered, but these would be subject to mounting restrictions. Therefore, it is not possible to design according to theory, and such countermeasures do not lead to fundamental improvements. Since the cab supported by the vehicle body frame through the cab suspension device in this manner has a high center of gravity, it is likely to take an inclined posture in the pitching direction or the rolling direction. That is, when the vehicle suddenly accelerates or brakes, or when the vehicle turns, the cab also tilts. According to the air suspension device, it is possible to provide a leveling function to some extent by the action of the leveling pulp, but due to the relationship between the passenger and the air pressure, the reaction time is long, and in the normal driving vibration range. , which often had the opposite effect. The present invention has been made in view of these problems, and is designed to suppress pitching or rolling of a cab supported through a cab suspension device, and to provide a force for restoring the cab to a fixed position. The purpose of this invention is to provide a cab mounting device. Means for Solving the Problems] The present invention provides a vehicle in which a cab is mounted on a vehicle body frame via a cab suspension venting device, which includes a hydraulic stabilizer for suppressing pitching or O-ring of the cab. The hydraulic stabilizer is interposed between the vehicle body frame and the cab, and a hydraulic power source is connected to chambers on opposite sides of a pair of hydraulic cylinders constituting the hydraulic stabilizer via a switching valve. 1 Effect 1 Therefore, pitching or rolling of the cab is suppressed by such a hydraulic stabilizer. Moreover, since the hydraulic source is connected to the chamber on the opposite side of the pair of hydraulic cylinders that make up the hydraulic stabilizer via the switching valve, the hydraulic stabilizer has a leveling function, and the switching valve By switching and supplying pressure oil to chambers on opposite sides of a pair of hydraulic cylinders, it is possible to restore the cab to its normal position.

【Example】

FIG. 1 shows a cab mounting device according to a first embodiment of the present invention, in which a cab 11 is mounted on the front end side of a body frame 10 of a truck. The cab 11 is elastically supported by front and rear suspension springs 12,13. A pair of hydraulic cylinders 15 and 16 constituting a hydraulic stabilizer are interposed between the cab 11 and the frame 10. The lower end of the front hydraulic cylinder 15 is connected to the front end of the frame 10, and the piston rod 17 is connected to the cab 11.
It is connected to the lower surface of the front end side. The rear hydraulic cylinder 16 is connected to the frame 10 at a position corresponding to the rear end of the cab 11, and its piston rod 18 is connected to the lower surface of the rear end of the cab 11. The pair of hydraulic cylinders 15, 16 are connected by a communication pipe 19, 20 so that the chambers on opposite sides communicate with each other. Moreover, accumulators 21, 22 are connected to these communication pipes 19, 20, respectively. The accumulators 21 and 22 are connected to a switching valve 23 that controls supply and discharge of hydraulic pressure. The rotational position of the switching valve 23 is controlled by a microcomputer 24. On the input side of the microcomputer 24, there is an accelerator sensor 28 that detects the amount of depression of the accelerator pedal 27, and a brake sensor 3 that detects the amount of depression of the brake pedal 29.
0, and an acceleration sensor 31 that detects acceleration in the longitudinal direction is connected to each of the sensors. Zarani Microcomputer 2
4 is the front and rear stroke sensor 33.34 of the cab 11
is now connected. These sensors 33.
34 are attached to the front and rear ends of the cab 11, respectively, and their detection levers are connected to the vehicle body frame 10 via link rods 35 and 36. Furthermore, a shift position sensor 38 provided in the transmission 37 is connected to the microcomputer 24. Figure 2 shows the switching valve 23 in the accumulator 21, 22.
shows a hydraulic source for supplying oil through
An oil pump 42 is linked to a drive source 41 consisting of a motor or a prime mover. The oil pump 42 is connected to a discharge pipe 43, and a relief pulp 44 is connected to the discharge pipe 43. Further, a reservoir 46 is connected to the return pipe 45 . Therefore, if the front end of the cab 11 supported by the cab suspension device consisting of front and rear suspension springs 12, 13 pitches downward, the piston of the front hydraulic cylinder 15 moves downward, causing the lower The oil in the chamber is supplied to the upper chamber of the rear hydraulic cylinder 16 through the conduit 19. As a result, the piston of the rear hydraulic cylinder 16 is pushed downward, and the rear part of the cab 11 is pulled downward. Furthermore, when a force is applied that causes the front end of the cab 11 to move upward, a force that suppresses this movement w1 is generated by the hydraulic cylinders 15, 16. In this way, pitching of the cab 11 is prevented by the hydraulic stabilizer consisting of the front and rear hydraulic cylinders 15, 16. As described above, according to the truck cab 11 bodywork device according to the present embodiment, the movement of the cab 11 in the pitching direction is controlled by the hydraulic stabilizer consisting of the oil cylinder 15.16 and the conduit 19.20 provided with the accumulator 21.22. will be suppressed. In addition, compared to a mechanical stabilizer using torsion bars, the degree of freedom in installation is increased, and the characteristics can be changed depending on the air filled in the accumulators 21 and 22, which allows for freedom in characteristics. It is possible to increase the degree. By suppressing the movement of the cab 11 in the pitching direction by such a hydraulic stabilizer, the spring 12 constituting the suspension II of the cab 11 is
．． 13 can be prevented from being significantly deformed, and bottoming of the cab 11 relative to the frame 10 can be prevented. Therefore, it becomes possible to improve the deterioration in riding comfort caused by bottoming. Since the cab suspension device is suspended on the chassis frame 10, the movement of the cab 11 roughly becomes a plane vibration relative to the frame 10. And the random input from the four-point spring 12.13 is
Less compared to chassis suspension. Regarding the component in the pitching direction, due to the truck's long wheelbase and large vehicle weight, the input from the unsprung area is small and the vibration period is long. For this reason, even if the suspension has a high spring constant only in the pitching direction, the ride comfort will not deteriorate that much, and in fact it will lead to an improvement in ride comfort in that a smaller stroke can be secured for the simple vertical component. Become. Furthermore, the hydraulic stabilizer consisting of the above-mentioned pair of hydraulic cylinders 15 and 16 has a leveling function.
1 to generate a restoring force to return it to its normal position. That is, the amount of deflection of the suspension springs 12 and 13 is made approximately O by forcibly supplying pressure oil from the hydraulic source shown in FIG. . Accumulator 2
Although it is possible to use air as the working fluid added to 1.22, it is preferable to use oil because it causes problems in response. Depressing the accelerator pedal 27 and the transmission 37
The gear position of the vehicle is detected by the accelerator sensor 28 and the shift position sensor 38, respectively, and a sudden start of the vehicle is thereby detected. In this case, since it is predicted that the cab 11 will tilt backward, the microcomputer 24 switches the switching valve 23 in this case. Further, the actual inclination of the cab 11 is detected by front and rear stroke sensors 33 and 34. In this case, the switching valve 23 is switched to a state opposite to that shown in FIG. 1 to supply pressurized oil into the accumulator 22 and drain the oil from the accumulator 21. This causes the pair of hydraulic cylinders 15, 16 to act to tilt the cab forward, thereby restoring the cab 11 to its normal position. When the brake pedal 29 is depressed, the brake sensor 30 detects this. In this case, the microcomputer 24 predicts that the front end of the cab 11 will tilt downward. Further, the actual inclination of the cab 11 is detected by a pair of stroke sensors 33 and 34. In such a case, the microcomputer 24 switches the switching valve 23 to the state shown in FIG. Therefore, pressure oil is supplied to the accumulator 21, and the accumulator 2
Oil is drained from 2. As a result, the hydraulic cylinders 15 and 16 apply a force that causes the cab 11 to tilt rearward, thereby restoring it to its normal position. Therefore, the hydraulic stabilizer for suppressing pitching of the cab 11 restores the cab 11 to its normal position. When the vehicle stops or runs at a constant speed, and the longitudinal acceleration falls below a certain value, the computer 24 determines that there is no longer any cause for the cab 11 to tilt, and the stroke sensors 33 and 34 are at the neutral position. The switching valve 23 is operated to return the cab 11 to the state shown in FIG. A pair of accumulators 21 and 22 through the switching valve 23
Instead of the configuration shown in FIG. 2, it is also possible to use a hydraulic power source configured as shown in FIG. 3 as a hydraulic source for selectively supplying pressure oil to. This hydraulic power source includes an accumulator 48 and a discharge pipe 43.
A 7-cumulator 48 is connected to. Moreover, a pressure switch 49 is provided on the accumulator 4, and the pressure detected by this pressure switch 49 is fed back to the drive source 41, and the oil pump 4 is fed back to the drive source 41.
2 control is performed. Therefore, the oil pump 42 is operated so that the pressure within the accumulator 48 is always maintained at a substantially constant pressure. FIG. 4 shows a hydraulic power source with yet another configuration,
This hydraulic source allows the microcomputer 24 to directly control the pressure in the accumulators 21, 22 by operating the servo motor 52. Note that signals from stroke sensors 33 and 34 are input to the computer 24. Further, a female threaded hole is formed in the center of the rotor 53 of the servo motor 52, and a feed screw 54 is engaged with this female threaded hole. A piston 55 is attached to the front end of the feed screw 54, and the piston 55 presses the oil in the cylinder 56. Such a servo motor 52 is connected to the accumulator 21.2.
According to the hydraulic power source of the type that is directly attached to the cylinder 56 of No. 2, not only the switching valve 23 and its attached piping are not required, but also an external hydraulic power source such as an oil pump is not required, making the hydraulic power source compact. It becomes possible to configure. Furthermore, control valves and magnetic valves are no longer required.
This makes it possible to reduce costs. It also has the advantage that the amount of circulating oil is reduced. Next, a modification of the first embodiment shown in FIG. 1 will be explained with reference to FIG. In this modification, the front and rear stroke sensors 33 and 34 are omitted, and the link rods 35 and 36 attached to the front and rear ends of the cab 11 are connected to the bell cranks 59 and 59 supported by the frame 10, respectively. I am trying to connect it to 60. The bellcrank 59.60 is further connected to both ends of the idler link 63 via links 61.62. The output end of the idler link 63 is connected to an arm 65 of the switching valve 23 via a bolt 64. That is, the idler link 63 constitutes a mechanical comparator, which detects the difference in leveling between the front end and the rear end of the cab 11, and switches the switching valve 23 in response to this detection. Further, in this modification, depression of the accelerator pedal 27 is detected by the accelerator switch 28, and
Depression of the brake pedal 29 is detected by a brake switch 30. Further, the shift position of the transmission 37 is detected by a shift position switch 38. The output sides of the brake switch 30 and the shift position switch 38 are connected to an AND gate 6.
It is connected to the input terminal of 6. And gate 66
The output terminal of the accelerator switch 28 and the output terminal of the accelerator switch 28 are connected to the input terminal of the OR gate 67. A logic circuit 68 is formed by the AND gate 66 and the OR gate 67, and the output of the logic circuit 68 controls the opening and closing of the electromagnetic valves 69 and 70 via the delay circuit 75 and its bypass circuit. Solenoid valve 69.70
is connected between the switching valve 23 and the accumulator 21 or 22. Also solenoid valve 69.7
A conduit 77 containing an orifice 76 is installed to allow slight communication of the oil in the accumulators 21, 22 even when the accumulators 21, 22 are closed. In the above configuration, when the shift position of the transmission 37 is 1st, 2nd, or 3rd gear and the accelerator pedal 27 is depressed, the switch 28
．． The outputs of 38 are both supplied to AND gate 66, which causes the output of gate 66 to become "1". This output passes through an or gate 67 to a pair of solenoid valves 6
It will open on 9.70. That is, when it is predicted that the cab 11 will pitch backwards due to the start of the vehicle, the solenoid valves 69 and 70 are opened. If the cab 11 tilts significantly backward due to a sudden start, the link rod 35
is moved upward, and the link rod 36 is lowered. The movement of these rods 35,36 is transmitted via bell cranks 59,60 and links 61,62 to idler link 63, which is moved to the left in FIG. This movement is transmitted to the arm 65 of the switching valve 23 via the rod 64, and the switching valve 23
will be rotated. As a result, the pressure oil from the hydraulic source is applied to the accumulator 22 through the switching valve 23 and the solenoid valve 70, and the oil in the accumulator 21 on the opposite side is discharged through the solenoid valve 69 and the switching valve 23. Become. Therefore, the pair of hydraulic cylinders 15.1e-- generate a force that lifts the rear part of the cab 11 and lowers the front part of the cab 11.
It operates to restore the body to its normal position. Next, when the brake pedal 29 is depressed, the brake switch 30 detects this and the output of the OR gate 67 becomes "1". This output opens the solenoid valves 69,70. Also, when the cab 11 moves forward at this time, the link rod 35 descends and
The link rod 36 rises. These rods 35.3
6 movement is a bell crank 59.60 and a link 61.6.
62 to the idler link 63. The idler link 63 is then moved to the right in FIG. This movement is transmitted to the switching valve 23 via the rod 64 and the arm 65, and the switching valve 23 is switched in the opposite direction to that in the above case. Therefore, in this case, the pressure oil from the hydraulic source is supplied to the switching valve 2.
3 and is supplied to the accumulator 21 which is connected to the line 19 through the solenoid valve 69. At the same time, the oil in the accumulator 22 on the opposite side connected to the pipe line 20 is discharged via the solenoid valve 70 and the switching valve 23. Therefore, the front hydraulic cylinder 15 acts to lift the front end of the cab 11, and the rear hydraulic cylinder 16 acts to pull the rear part of the cab 11 downward. This prevents the cab 11 from pitching forward during sudden braking and restores it to its normal position. If the solenoid valves 69 and 70 are immediately closed when the vehicle is stopped or running at a constant speed and the cause of the cab 11 tilting disappears, the effect of forced leveling by hydraulic pressure remains, and the cab 11 tilts. There is a risk that it will remain tilted. Therefore, due to the function of the delay circuit 75, the cab 1
The solenoid valves 69 and 70 are kept open for a certain period of time until the behavior in step 1 settles down. Also, any remaining oil imbalance is gradually resolved through the orifice 76. Therefore, even in such a system,
The same operation as in the first embodiment described above can be performed. Next, a second embodiment will be explained with reference to FIG. In this embodiment, a pair of hydraulic cylinders 15 and 16 are arranged on the left and right sides, thereby suppressing rolling. The hydraulic cylinders 15 and 16 are connected to the left and right frames 10, respectively, and their piston rods 17 and 18 are connected to the left and right sides of the cab 11. Further, stroke sensors 33 and 34 detect the distance between the left and right sides of the cab 11 and the frame 10, respectively. Further, on the input side of the microcomputer 24 that controls the switching of the switching valve 23, in addition to the stroke sensors 33 and 34, a steering sensor 72 that detects the steering angle of the steering handle 71 is connected to the input side of the microcomputer 24 that controls the switching of the switching valve 23. It is connected to a vehicle speed sensor 73 that detects the vehicle speed and an acceleration sensor 74 that detects the acceleration of the cab 11 in the left and right direction. According to this embodiment, therefore, a pair of hydraulic cylinders 15.
The lateral movement, or rolling, of the cab 11 is suppressed by the hydraulic stabilizer consisting of 16. Furthermore, when the microcomputer 24 predicts that the cab 11 will roll based on the detection outputs of the steering sensor 72 and the vehicle speed sensor 73, the microcomputer 24 switches the switching valve 23. Also, when the lateral acceleration sensor 74 detects that lateral acceleration is applied to the cab 11, the microcomputer 24 switches the switching valve 23. With such switching of the switching valve 23, pressure oil from the hydraulic source is supplied to the accumulator 21 or 22. Therefore, for example, when the left side of the cab 11 is about to move downward in FIG. The piston rod 18 is retracted, pulling the right side of the cab 11 downward. As a result, the cab 11 is not only prevented from rolling, but also receives a force that restores it to its normal position. If the cab 11 tries to tilt to the right, the left and right hydraulic cylinders 15, 16 perform operations opposite to those described above to restore the cab 11 to its normal position. Furthermore, by combining this second embodiment with the first embodiment described above, a cab suspension device that exhibits the respective functions can be obtained. Effects of the Invention 1 As described above, the present invention provides a hydraulic stabilizer that suppresses pitching or rolling of the cab between the vehicle body frame and the cab, and connects the hydraulic source to the hydraulic stabilizer via the switching valve. It is connected to chambers on opposite sides of a pair of hydraulic cylinders. Therefore, the hydraulic stabilizer not only suppresses pitching or rolling of the cab, but also supplies pressure oil to a predetermined chamber of the hydraulic cylinder that constitutes the hydraulic stabilizer through the switching valve, thereby keeping the cab in a fixed position. It is now possible to restore to
It becomes possible to add a leveling function to the hydraulic stabilizer.

[Brief explanation of the drawing]

Figure 1 is a piping diagram showing the cab mounting system of the first embodiment, Figure 2 is a piping diagram showing the configuration of the hydraulic power source, Figure 3 is a piping diagram of the hydraulic power source of a modified example, and Figure 4 is a piping diagram showing the configuration of the hydraulic power source. FIG. 5 is a longitudinal cross-sectional view of another modification of the hydraulic power source, FIG. 5 is a piping diagram of the mounting device of the modification, and FIG. 6 is a piping diagram of the mounting device of the second embodiment. The names of the main parts in the drawings are as follows. 10... Body frame 11... Cab 12.13... Suspension spring 15.16... Hydraulic cylinder 19.20... Communication pipe 21.22... Accumulator 23. ...Switching valve 42...Oil pump 48...Accumulator

Claims (1)

[Claims] 1. In a vehicle in which a cab is mounted on a body frame via a cab suspension device, a hydraulic stabilizer for suppressing pitching of the cab is interposed between the body frame and the cab. What is claimed is: 1. A cab mounting device, characterized in that a hydraulic power source is connected via a switching valve to chambers on opposite sides of a pair of hydraulic cylinders constituting the hydraulic stabilizer. 2. In a vehicle in which a cab is mounted on a body frame via a cab suspension device, a hydraulic stabilizer for suppressing rolling of the cab is interposed between the body frame and the cab, and a switching valve is provided. A cab mounting device characterized in that a hydraulic power source is connected to mutually opposite chambers of a pair of hydraulic cylinders constituting the hydraulic stabilizer.