JPH0127201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Purpose) The present invention relates to a tamping device for a track straightening machine.

(Prior art) The tamping device of a track straightening machine is a device that uses a vibrating tool to compact the ballast laid on the track bed.As a type of tamping device, the tool vibration mechanism is driven by a hydraulic motor. There is something to drive it. Conventionally, constant displacement hydraulic pumps (hereinafter referred to as constant displacement pumps) have been used exclusively as hydraulic pumps for sending hydraulic pressure to the hydraulic motors.

(Problems to be Solved by the Invention) By the way, the tamping device can be used depending on the condition of the roadbed (for example, a compacted roadbed, a gravel section, a crushed stone section, etc.), the degree of consolidation of the roadbed, the shape and size of the ballast, etc. ) The load applied to the tamping tool inserted into the gravel of the road bed changes, but in order to respond to this change in load, conventional fixed displacement pumps either use a throttle valve to change the amount of oil flowing to the hydraulic motor, or The only way to do this was to change the rotation speed of the prime mover. However, in the method using a throttle valve, it is necessary to return excess oil to the tank using a relief valve or the like, which causes the relief valve to generate heat. Additionally, the method of changing the rotational speed of the prime mover could not be adopted because in most cases the prime mover also drives other hydraulic pumps, which would reduce the performance of other parts and lead to a decrease in the machine's capacity. .
Furthermore, in a tamping device in which a hydraulic motor is controlled by a constant displacement pump, it is practically impossible to adjust the vibration frequency of the tool depending on the condition of the track bed. In addition, even if an overload is applied to the tool side, a constant displacement pump discharges a constant flow rate, so repeated maximum loads may eventually lead to failure or destruction of the tamping device. It was hot. Furthermore, in order to address the above-mentioned drawbacks, it is necessary to increase the size of the hydraulic device, tamping device, etc., and the amount of oil used also increases, which is not desirable in practice.

The present invention solves the above-mentioned drawbacks by using a variable displacement hydraulic pump (e.g., a rotating swash plate type axial plunger pump, hereinafter referred to as variable pump) as a drive source for a hydraulic motor for driving the vibration generating part of a tamping device. In particular, when a load is applied to the tool of a tamping device, the angle of the swash plate is automatically changed via a spring cylinder according to the magnitude of this load, and the discharge of a variable pump is improved. By increasing/decreasing the amount of vibration and increasing/decreasing the discharge pressure applied to the hydraulic motor for driving the vibrator within a predetermined range, it is possible to prevent the entire device from overloading, and the tool can also be adjusted to a predetermined frequency and excitation. An object of the present invention is to provide a tamping device for a track straightening machine that can obtain vibration force.

[Structure of the invention]

(Means for Solving the Problems) The tamping device of the track straightening machine of the present invention includes a variable displacement hydraulic pump attached to a mounting frame and driven by a prime mover; driven by the variable displacement hydraulic pump. a hydraulic motor for driving the vibration generating part;
A tamping mechanism consisting of a tool vibration mechanism that is driven by the hydraulic motor for driving the vibration part and vibrates the tool, and a tool that is vibrated by the tool vibration mechanism and compacts the ballast; can be freely slid into the outer cylinder. an operating shaft incorporated in the operating shaft; a spring cylinder having a coil spring that restricts the sliding of the operating shaft with respect to the outer cylinder; an adjusting means for adjusting the spring pressure of the coil spring of the spring cylinder; the variable displacement hydraulic pump; a first operating mechanism connecting the spring cylinder; a rod connected to the operating shaft of the spring cylinder via a second operating mechanism, the base of which is connected to the mounting frame via a shaft provided with guides at both ends; an operating hydraulic cylinder held by the operating hydraulic cylinder; the tip is connected to the lower end of the second operating mechanism together with the rod of the operating hydraulic cylinder via a support shaft, and a shaft with guides provided at both ends is connected near the rear end; and a slide plate that is held in the mounting frame through the slide plate, has a guide hole for sliding the guide, and has a stroke adjustment mechanism attached to the rear end to adjust the stroke of the rod of the operating hydraulic cylinder. Features.

(Function) In the present invention having the above configuration,
By adjusting the stroke of the operating hydraulic cylinder, the inclination angle of the swash plate is set to a value with a certain width, a spring with an appropriate spring constant is selected for the spring of the spring cylinder, and the spring is applied to the tool of the tamping mechanism. The reaction force coming from the variable pump side is held by the operating hydraulic cylinder via a spring cylinder according to the increase or decrease in load, and the inclination angle of the swash plate changes according to the increase or decrease in load. The rotation speed of the hydraulic motor is changed to change the vibration frequency of the tool, and a discharge pressure, that is, an excitation force (a force that applies vibration to the ballast) is applied to the tool within a predetermined range.

(Examples) Hereinafter, the present invention will be specifically described based on illustrated examples.

*Configuration of Embodiment* FIG. 1 is a hydraulic main circuit diagram of a tamping device for a track straightening machine according to the present invention, in which reference numeral 1 indicates a variable pump and 2 indicates a prime mover as its driving source. 3 is a tamping mechanism. This tamping mechanism 3 includes a hydraulic motor 3a for driving an oscillating part, and a hydraulic motor 3a for driving a vibrating section.
a tool vibration mechanism 3b that is driven by the tamping tool a and vibrates the tamping tool;
It consists of a tool 4 which is given vibration by b. The tamping mechanism 3 can be moved up and down by a vertical movement mechanism (not shown), and the tool 4 can be opened and closed in the longitudinal direction of the rail across the sleepers by an opening/closing mechanism (not shown). It's getting old. Furthermore, this tamping mechanism 3
are placed on the left and right rails, respectively. Furthermore, a pressure oil circulation circuit 5 is provided between the variable pump 1 and the hydraulic motor 3. A replenishment circuit 6 for replenishing leakage of pressure oil is connected to the circulation circuit 5. This replenishment circuit 6 is connected to a replenishment pump 8, and a check valve 6' is connected to the replenishment pump 8. Oil is replenished into the circulation circuit 5 through. The variable pump 1 is connected to a leak circuit 1' for returning leakage from the variable pump 1 to the tank 7, and the tank 7 and the replenishment pump 8 are connected by a suction circuit 8'.

Figures 2a and 3 are front and side views showing the swash plate adjustment mechanism of the variable pump of the tamping device of the track straightener of the present invention, and Figure 2b is the c-c cross section of Figure 2a. In the figure, reference numeral 11 denotes a mounting frame for the variable pump 1. This mounting frame 11 is provided on the truck of the track straightening machine, and the variable pump 1 is fixed to the top thereof by means such as bolt tightening. Further, a replenishment pump 8 is also fixed to the top of the mounting frame 11 so as to face the variable pump 1. On the outer wall of the variable pump 1,
A support shaft 12 of the swash plate 1a incorporated in the pump is exposed, and this support shaft 12 is connected to a support shaft 34 of the spring cylinder 30 via the first operating mechanism 10a.

The first operation mechanism 10a includes an operation lever 13 fixed to a support shaft 12, a joint 14 and a connecting rod 15 connected to the upper end of the operation lever 13, and a second operation lever 13 whose upper end is connected to the joint 14 by a pin joint. 1 transmission lever 16. This first transmission lever 16 is rotatably attached to a fulcrum at the top of a bracket 17 provided on the mounting frame 11. The lower end of the first transmission lever 16 is connected to a support shaft 34 of a spring cylinder 30 (the structure of which will be described later). One end of the operating shaft 31 of the spring cylinder 30 is connected to the rod 20 of the operating hydraulic cylinder 19 via the second operating mechanism 10b. In this embodiment, the second operating mechanism 10b has its upper end connected to the spring cylinder 30 using a pin.
It consists of a second transmission lever 18 connected to one end of the operating shaft 31 and the lower end connected to the rod 20 of the operating hydraulic cylinder 19, and, like the first transmission lever 16, a bracket 19' provided on the mounting frame 11. It is attached to the top of the holder and swings back and forth using the top 19' as a fulcrum.

The operating hydraulic cylinder 19 is provided with a stroke adjustment mechanism for the rod 20, as shown in FIG. 2b. That is, the rod 2 is placed on the side of the cylinder 19.
A slide plate 21 is provided which reciprocates with 0, and the tip of this slide plate 21 is connected to the lower end of the second transmission lever 18 via a support shaft 21b. Further, the vicinity of the rear end of the slide plate 21 is held by the mounting frame 11 via the base 19a of the cylinder 19, a shaft 23a provided with guides at both ends, and a support 11a. Further, a guide hole 22 is formed in the slide plate 21 along the longitudinal direction, and this guide hole 22
Inside, a guide 23 of a shaft 23a having guides provided at both ends is adapted to slide. Also,
The rear end of this slide plate 21 is connected to the cylinder 1.
By making the rod 20 protrude further rearward than the base 19a of the rod 9, and attaching an adjustment bolt 24 to that portion 21a, and adjusting this adjustment bolt 24, the rod 20 moves in the direction of arrow A, and the adjustment bolt 24 When the tip of the rod 19 hits the base 19a of the cylinder 19, and the forward movement of the rod 20 beyond a certain amount is prevented, the swash plate 1a of the variable pump 1 responds to the compressive force of the spring of the spring cylinder 30, as shown in FIG. 4b. When the angle is balanced, that is, the angle of inclination is α, and the flow rate of the variable pump 1 is adjusted.

On the other hand, the spring cylinder 30 has a configuration shown in FIGS. 5 and 6.

In the figure, reference numeral 31 denotes an operating shaft disposed at the center of the spring cylinder 30, and one end of this operating shaft 31 is connected to the upper end of the second lever 18 as described above. Operation axis 31
A flange-shaped locking portion 32 is integrally provided at the center of the holder. An outer cylinder 33 is fitted into the outer periphery of the operating shaft 31, and the first transmission lever 16 is attached to a support shaft 34 provided on the central surface of the outer cylinder 33.
Connect the bottom ends of. This outer cylinder 33 is connected to the operation shaft 31
Bearings 35 are provided at both front and rear ends of the outer cylinder 33 so that the outer cylinder 33 is fitted onto the outer periphery of the operating shaft with an appropriate distance between the outer cylinder 33 and the outer periphery of the operating shaft.
It is possible to slide in the axial direction of 1. This bearing 35
has a substantially ring shape, and its outer peripheral portion is screwed onto the inner surface of the end portion of the outer cylinder 33, and a sliding portion is formed between the inner surface of the bearing 35 and the outer surface of the operating shaft 31.
In addition, since the outer periphery of the bearing 35 and the inner periphery of the outer cylinder 33 are attached in a screwed state, it is possible to change the spring force as appropriate by adjusting the screwing degree of the bearing 35. Both ends of the outer cylinder 33 (only the case provided at one end is shown in the figure)
A stopper 36 is provided to prevent rotation of the bearing 35 screwed thereon. Further, a step portion 37 for a spring receiver is integrally formed inside the bearing 35.

On the other hand, between the operating shaft 31 and the outer cylinder 33, there is a
It incorporates a pair of left and right slide rings 38,
This slide ring 38 is connected to the operation shaft 31 and the outer cylinder 33.
It is movable for both. The two slide rings 38 are arranged so as to sandwich the locking portion 32 at the center of the operation shaft, and when the tool 4 is not being vibrated, the slide rings 38 and the locking portion 32 are in contact with each other and engaged. do. (The state of Fig. 4 a, α
=0). Furthermore, the step portion 39 of the bearing 35 is formed on the slide ring 38 . Further, between the operating shaft 31 and the outer cylinder 33, a pair of coil springs 40 are fitted in a compressed state on the outer periphery of the operating shaft 31 with the locking portion 32 in between, and the ends thereof are connected to the bearing 35 and the slide ring 38. Stepped portion 37 for spring support provided in
It is locked at 39.

*Function of the embodiment* The tamping device of the track straightening machine of the present invention has the configuration as shown in the above-mentioned embodiment, but
Next, its effect will be explained.

First, the adjustment bolt 24 of the stroke adjustment mechanism
is adjusted so that the maximum discharge amount is delivered when the swash plate 1a of the variable pump 1 is tilted by α. Also,
Select an appropriate spring constant for the spring of the spring cylinder, and adjust the spring pressure of this spring to the bearing 35 as necessary.
Adjust by the screw-in amount. For example, if a compacted trackbed is expected, the spring 40 is adjusted to be compressed, and if it is a newly constructed track, the spring 40 is adjusted so as not to be compressed too much. Next, the variable pump 1 is driven by the prime mover 2. That is, the oscillation switch (not shown)
In the OFF state (when stopping work, finishing work, sending the track straightening machine, etc.), it is in the state shown in Figure 4 a (α = 0), but the vibration switch is turned ON while the tool 4 remains in the air. When the operating hydraulic cylinder 19 is activated, the rod 20 is moved to the adjusting bolt 2.
By operating the swash plate 1a up to the maximum stroke set in step 4, the swash plate 1a interlocked therewith via a spring cylinder is tilted to an angle α. Specifically, when the operation cylinder 19 is operated, the second transmission lever 18 connected to the tip of the rod 20 swings, and the operation shaft 3 of the spring cylinder connected to the upper end of the second transmission lever 18 swings.
1 moves. This movement of the operating shaft 31 is transmitted to the outer cylinder 33 via the locking portion 32 at the center of the operating shaft, the slide ring 38, the coil spring 40, and the bearing 35. In this case, no matter which direction the operating shaft 31 moves, the movement is transmitted to the outer cylinder 33 via the left or right slide ring or coil spring, and the outer cylinder 33 also moves together with the operating shaft 31. When the outer cylinder 33 moves, the first transmission lever 16 connected to the support shaft 34 also swings, and as a result, the first transmission lever 16
The operating lever 13, which is connected via the joint 14 and rod 15, also moves, and the swash plate of the variable pump 1 becomes the set angle α [see Figure 4b]. The hydraulic motor 3a rotates, and the tool vibrates according to the rotation speed.

When the tool 4 is inserted into the solidified track bed in this state, the load applied to the tool 4 becomes large, and the discharge pressure (reaction force) of the P section of the cylinder in the variable pump 1 reaches a predetermined value, and this discharge pressure It works to reduce the angle α of the plate 1a. This discharge pressure is applied to the operating lever 13 via the swash plate, and on the other hand, the operating cylinder 19
is the full stroke (adjusting bolt 24 is in cylinder 1)
9), the swash plate 1a stops when the discharge pressure and the spring pressure of the spring cylinder 30 are balanced. In this case, the inclination of the swash plate 1a becomes smaller than α, the flow rate decreases, and the vibration frequency of the tool also decreases, but since the discharge pressure P is within a predetermined range, the excitation force does not change much. In addition, when the roadbed gravel is crushed stone, gravel, etc., the inclination of the swash plate 1a approaches α, so the flow rate is large and the vibration frequency is also larger than that of a compacted roadbed, but the discharge pressure P is within a predetermined range. The excitation force does not change much. In this way, swash plate 1
The inclination angle of 9 is the smallest for the consolidated roadbed, followed by crushed stone and gravel, but the excitation force changes within a predetermined range. .

In this embodiment, an adjustment bolt 24 is provided at the rear end of the slide plate 21 that is linked to the cylinder 19.
is attached, thereby adjusting the stroke of the rod 20 of the operating hydraulic cylinder 19. That is,
By adjusting the screwing amount of this adjustment bolt 24, the inclination angle of the swash plate (usually 18 degrees to 20 degrees) can be adjusted.
The maximum oil discharge amount of the variable pump can be adjusted by changing the rotation speed of the hydraulic motor 3a for driving the vibration generator of the tamping device, so the vibration frequency of the tamping tool can be changed.
That is, when the adjusting bolt 24 is adjusted so as to move the rod side of the operating hydraulic cylinder in the direction of arrow A, the inclination angle α of the swash plate increases, and the discharge amount from the variable pump 1 increases. On the other hand, if the above adjustment is reversed, the discharge amount from the variable pump 1 will decrease.

Next, the action of the spring cylinder 30 will be explained in detail.
When the vibrating tool 4 is inserted into the trackbed as described above and an overload is applied to the variable pump 1 from the tamping device side, the discharge pressure of the P section of the cylinder in the variable pump 1 increases, and this discharge Pressure is swash plate 19
It works to reduce the inclination angle α. The reaction force applied to the swash plate is transmitted to the operating lever 13 outside the variable pump, and is further transmitted to the outer cylinder 3 of the spring cylinder 30 via the joint 14, rod 15, and first transmission lever 16.
3, and moves this outer cylinder 33, for example, in the direction of the arrow B in the figure. In this case, the spring cylinder 30
Since the operating shaft 31 is held in a fixed position and cannot be moved by the operating hydraulic cylinder 19 connected via the second transmission lever 18, only the outer cylinder 33 is moved as shown in FIG. slides along the operating shaft 31. In addition, when sliding the outer cylinder 33, one slide ring 38 (on the right side in the figure)
comes into contact with the locking portion 32 of the operating shaft 31 and is prevented from moving together with the outer cylinder 33, so the coil spring 40 provided between the slide ring 38 and the bearing 35 is compressed. As a result, the swash plate 1a stops at a point where the discharge pressure applied to the swash plate and the compression force of this coil spring 40 are balanced (becomes smaller than the set angle α), and the variable pump discharge oil amount decreases. Although the rotational speed of the vibration excitation hydraulic motor 3a decreases, the excitation force does not change much, and overload of the device is prevented. Note that once the overload is removed, the coil spring 4 compressed within the spring cylinder
Due to the restoring force of 0, the outer cylinder 33 returns to its original state, and the swash plate also returns to the operating hydraulic cylinder 19.
Returns to the maximum discharge angle corresponding to the setting value.

In addition, in the spring cylinder 30, the point at which the outer cylinder 33 starts to move on the operating shaft 31, that is, the degree of the buffering effect by this spring cylinder and the strength of the excitation force to be applied to the tool are determined by the spring cylinder 30.
It can also be adjusted by the screwing amount of the bearing 35 provided in the. For example, if the bearing 35 is
If the tool is screwed in deeply, the degree of compression of the coil spring 40 increases, and a large force is required to slide the outer cylinder 33, and the excitation force applied to the tool changes within a predetermined range.

Note that the above explanation was about the case where the work is performed by vibrating the tool, but
As described above, when it is set to OFF, the situation is as shown in FIG. 5a.

〔Effect of the invention〕

As described above, according to the present invention, when a load is applied to the vibrating tamping tool, the swash plate stops tilting when the reaction force applied to the swash plate of the variable pump and the spring cylinder are balanced. Since the discharge amount of pressure oil is controlled and the excitation force applied to the tool is also varied within a predetermined range, overload of the device can be prevented, and there is no risk of malfunction or destruction of the tamping device. As a result, the variable pump can be used without any problem for driving a tamping device with large load fluctuations. In addition, when the discharge amount of the variable pump changes and the discharge pressure changes within a predetermined range, the frequency of the tool of the tamping device changes and the excitation force also changes within a predetermined range. The number and excitation force can be obtained. Furthermore, it is possible to downsize the device, reduce the amount of oil used, and save energy, which has great industrial effects.

Further, in the present invention, since the spring cylinder is provided with a pressure adjustment means for a coil spring built into the cylinder, and the operating hydraulic cylinder is provided with an adjustment means, the movement of the operating shaft when a load is applied is used. It becomes possible to adjust the starting point, ie the starting point of the damping effect by the spring cylinder. As a result, the point at which the tool's vibration frequency begins to change in response to load changes can also be freely adjusted.
This makes it possible to obtain the most appropriate tool frequency and excitation force to match the track bed in various conditions.

Note that the present invention is not limited to the illustrated embodiment, and other means than the illustrated first and second transmission levers may be used as a means for connecting the operating lever and the spring cylinder, or the operating hydraulic cylinder and the spring cylinder. Can be used. It is also possible to connect the operating hydraulic cylinder to the outer cylinder of the spring cylinder.

[Brief explanation of drawings]

FIG. 1 is a hydraulic main circuit diagram of the tamping device of the track straightening machine of the present invention, FIG. 2a is a front view of the swash plate adjustment mechanism of the variable pump of the tamping device of the track straightening machine of the present invention, FIG. FIG. 3 is a side view of FIG. 2 a, FIGS. 4 a and b are schematic mechanical diagrams of the main parts of the present invention, and FIGS. 5 and 6 are cross-sectional views of the present invention. It is a sectional view showing a spring cylinder in the device. DESCRIPTION OF SYMBOLS 1... Variable pump, 1a... Swash plate, 3... Tamping mechanism, 3a... Hydraulic motor for driving vibration part,
3b... Vibration mechanism, 4... Tool, 7... Tank, 8... Auxiliary pump, 10a... First operating mechanism, 10b... Second operating mechanism, 19... Hydraulic cylinder for operation, 24... Adjustment bolt, 30...Spring cylinder, 31...Operation shaft, 33...Outer cylinder, 3
5...Bearing, 38...Slide ring, 40...
coil spring.

Claims (1)

[Claims] 1. A variable displacement hydraulic pump attached to the mounting frame and driven by a prime mover; A hydraulic motor for driving an excitation section driven by this variable displacement hydraulic pump; and a hydraulic motor for driving an excitation section driven by this hydraulic motor for driving an excitation section. a tamping mechanism that includes a tool vibration mechanism that vibrates the tool; and a tool that is vibrated by the tool vibration mechanism and compacts the ballast; an operating shaft that is slidably incorporated in the outer cylinder; a spring cylinder having a coil spring that restricts the sliding of the operation shaft with respect to the outer cylinder; an adjustment means that adjusts the spring pressure of the coil spring of the spring cylinder; a spring cylinder that connects the variable displacement hydraulic pump and the spring cylinder; 1 operating mechanism; an operating hydraulic pressure having a rod connected to the operating shaft of the spring cylinder via a second operating mechanism, the base of which is held in the mounting frame via a shaft provided with guides at both ends; A cylinder; the tip is connected to the lower end of the second operating mechanism together with the rod of the operating hydraulic cylinder via a support shaft, and the vicinity of the rear end is held in the mounting frame via a shaft provided with guides at both ends. and a slide plate provided with a guide hole for sliding the guide and a stroke adjustment mechanism attached to the rear end to adjust the stroke of the rod of the operating hydraulic cylinder. Machine tamping device.