JPH02190503A - Device for measuring cutting depth for road surface cutting machine - Google Patents

Abstract

PURPOSE:To make accurate measurement of cutting depth and tilting of a cutter drum available by applying computer processing based on detected values that have been detected by a turn angle sensor installed to a cutter drum and by a force sensor jointly installed to one of cutter bits that are provided to the cutter drum. CONSTITUTION:A plurality of cutter bits 2 are provided to the peripheral surface of a cutter drum 1 that is suspended from the belly of a body of a road surface cutting machine. A turn angle sensor made from a potentiometer 12 or the like is installed to the cutter drum 1 for detecting the turn angle of the cutter drum 1. At least each one of the cutter bits 2 that is provided respectively at each of the opposite ends of the cutter drum 1 is respectively made a sensor bit 31 or 32, and each one force sensor is jointly installed thereto for detecting variation of force acting on each of the bits 31 and 32. The detected values are then sent to a display device for computer processing, where necessary computerization is applied to the values, and cutting depth at both ends of the cutter drum 1 and tilting condition of the cutter drum 1 are computed and displayed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cutting depth measuring device for a road cutting vehicle.

[Conventional technology]

-a, the road cutting vehicle is equipped with a cylindrical cutter drum 61 on the abdomen of the vehicle body 60, as shown in FIG. As shown in FIG. 9, a large number (several tens) of cutter bits 62 for cutting the road surface are provided on the outer circumference of the cutter drum 61.

Then, while moving the car body 60, the cutter drum 61 is rotated at about several tens of revolutions per minute, and the cutter bit 6 is rotated.
2 is lowered onto the road surface to continuously cut the road surface.

Further, the vehicle body 60 has front wheels 62. The rear wheels 63 are supported above the wheels through jack-type vehicle body support means 64 and 65, each of which includes a pair of hydraulic cylinders installed above the rear wheels 63, respectively. The height and inclination of the vehicle body can be adjusted by controlling these vehicle body support means 64, 65 using a vehicle height adjustment controller 67 provided at the rear of the vehicle body.

In this case, the cutting depth can be determined by measuring the amount by which the cutter bit 62 sinks from the road surface, but this is dangerous, so conventionally, the cutting depth is determined by measuring the vertical distance (height) from the road surface to the bottom of the car body ) is determined indirectly by methods such as measuring.

[Problem to be solved by the invention]

However, with the above-mentioned conventional method for measuring cutting depth, accurate measurement cannot be performed due to the effects of road surface irregularities, wheel flexure, vehicle body rattling (vibration), and the like. In particular, if the cutter drum is tilted while cutting the road surface due to some reason such as unevenness of the road surface, and there is a difference in the amount of penetration of the cutter bit into the road surface (the amount of sinking from the road surface) at both ends of the cutter drum, the cutter bit It is difficult to accurately determine the amount of penetration of the cutter drum into the road surface, and there is a disadvantage that there is a difference in cutting depth at both ends of the cutter drum.

[Object of the Invention] The object of the present invention is to improve the disadvantages of the prior art, and in particular, to measure the cutting depth at both ends of the cutter drum and the inclination of the cutter drum without causing any danger during cutting. It is an object of the present invention to provide a cutting depth measuring device for a road cutting vehicle that can display the results.

[Means to solve the problem]

The present invention includes a cylindrical cutter drum that is rotatably supported on the abdomen of the vehicle body, and a plurality of cutter bits that are provided on the outer circumferential portion of the cutter drum over almost the entire front surface thereof. Then, a rotation angle sensor is attached to the cutter drum to detect the rotation angle of the cutter drum, and
At least one of the cutter bits located at both ends of the cutter drum is provided with a force sensor that electrically detects a change in the force acting on the cutter bit.

Furthermore, a calculation processing display means is provided for calculating and displaying the cutting depth at both ends of the cutter drum and the inclination of the cutter drum by performing predetermined calculations based on the output signals of the force sensor and the rotation angle sensor. There is. This aims to achieve the above-mentioned objective.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

Similar to the conventional example described above, this embodiment includes a cylindrical cutter drum 1 rotatably supported on the abdomen of a vehicle body 31 of a road cutting vehicle 30 shown in FIG. The vehicle body 31 is
Rear wheel 32. The front wheels 33 are supported above the wheels through jack-type vehicle body support means 34 and 35 each having a pair of hydraulic cylinders installed above the wheels. The height and inclination of the vehicle body can be adjusted by controlling these vehicle body support means 34, 35 using a vehicle height adjustment controller 37 provided at the rear of the vehicle body.

As shown in FIG. 1, on the outer periphery of the cutter drum 1, a plurality of road surface cutting canterpipes 2, 2. ...... is provided. Among these, one of the cutter bits arranged at predetermined intervals along the circumferential direction of the cutter drum 11 in the rows at both ends (the one located at the bottom end in FIG. 1) is the sensor bit 33, 3 □ , and the rest are regular cutter bits 2
(See Figure 2).

Among these, sensor bit 3. The internal structure of is shown in Figure 4. In this FIG. 4, on the outer surface of the cutter drum 1,
A cylindrical cutter bit sleeve 4 protruding outward (downward in the figure) is welded. Inside the cutter bit sleeve 4, a force sensor lit is installed in the upper part of the figure to electrically detect changes in force.

Force sensor 11. For example, a device that converts force into an electrical signal, such as a load cell or a strain gauge, is used. A cutter bit 2A formed in a cylindrical shape is provided below the sensor 111 in the figure with a spring 5 interposed therebetween.

To explain this in more detail, the tip of the cutter bit 2A is formed into a conical shape, and a ring 6 for preventing falling off is attached to the base end. The cutter bit 2A is mounted on the cutter bit sleeve 4 with the ring 6 loosely fitting into the groove 4a formed on the inner peripheral surface of the cutter bit sleeve 4. Therefore, when the tip of the cutter bit 2A touches the ground, the cutter bit 2A moves upward due to the reaction force from the ground, and the reaction force is transmitted to the force sensor lit via the spring 5. ing.

The remaining sensor bit 3 □ located at the opposite end of the cutter drum 1 is also configured in the same manner as the sensor bit 13 .

On the other hand, the rotary shaft portion of the cutter drum 1 described above is equipped with a potentiometer 12 as a rotation angle sensor for detecting the rotation angle of the cutter drum 1, as shown in FIG.

FIG. 5 shows an example of a circuit when a load cell is used as the force sensor 11. This load cell utilizes the principle of a strain gauge type force sensor, in which a strain gauge for detecting strain is attached to an elastic body (not shown), and the strain is converted into an electrical signal by a bridge circuit. On the other hand, the potentiometer 12 is a type of variable resistor whose resistance value changes in proportion to the rotation angle (see FIG. 7 (2)).

In this embodiment, these load cells 111.11□ and potentiometer 12 are connected to a power source 9 as shown in FIG.
are connected in parallel. At the output stage of each load cell,
differential amplifiers 13. through resistors 21.22, respectively. ．．
13□ is connected.

An A/D (analog-digital) converter 15 is also provided at the output stage of these operational amplifiers 131.13□. Potentiometer 12 and A/D converter 15
A sample hold 14 as a rotation angle signal holding means for holding the output of the potentiometer 12 in response to a command from an arithmetic control means to be described later is interposed between the two. Furthermore, the output stage of the A/D converter 15 includes a sample hold 1.
4 and performs predetermined calculations based on the output of the sample hold 14 to calculate the cutting depth and the inclination of the cutter drum 1. That is, this arithmetic control means 16 is actually composed of a microcomputer, etc., and receives the output signals of the operational amplifiers 131 and 132 via the A/D converter 15, thereby causing the outputs of the load cells 11+ and 11g to suddenly change. When the change occurs, it is detected, the output of the potentiometer 12 at this time is held in the sample hold 14, the output signal of the sample hold 14 is received via the A/D converter 15, and a predetermined calculation is performed based on this. Furthermore, the calculation control means 16 which calculates the cutting depth and the inclination of the cutter drum 1 is also provided with a display means 17 which displays the calculation results.

In this embodiment, the sample hold 14 and the A/D converter 1
5, the calculation control means 16, and the display means 17 constitute a calculation processing display means 20.

Next, the principle of calculating the cutting depth in this embodiment will be explained based on FIG. 6.

In FIG. 6, OA is a vertical line passing through the rotation center 0 of the cutter drum 1 (a perpendicular line drawn from the car body 31 to the rotation center 0), and point B is the point where the sensor bit 3 contacts the road surface and starts cutting, θ represents the angle from when the sensor bit 3 is grounded to when it passes through the vertical line OA. Further, the symbol r indicates the length from the center 0 of the cutter drum 1 to the tip of the cutter bit 2A constituting the sensor bit 3.

From these relationships, the cutting depth h can be determined by the following equation.

h=r (1-cosθ)・・・・・・・・・・・・0
Next, the function and operation of the above embodiment will be explained.

Here, for convenience of explanation, sensor bit 3. I will explain about it.

First, when the cutter drum 1 rotates in the direction of arrow C in FIG. 6 and the sensor bit 3I starts cutting the road surface at point B, the sensor bit 3I starts cutting the road surface at point B. The two cutter bits installed at the tips of the cutter bits receive backlash from the road surface. This reaction force is applied to the load cell 11 via the spring 5. The resistance network constituting the load cell 11 in FIG. 5 changes, and the output voltage of the operational amplifier 131 suddenly increases at point B as shown in FIG. 7(1). The arithmetic control means 16 detects this change in the output voltage via the A/D converter 15, and causes the sample hold 14 to hold the output voltage of the potentiometer 12 at this time.

This output voltage is converted into a digital value by the A/D converter 15 and sent to the arithmetic control means 16.

The arithmetic control means 16 determines in advance the relationship between the rotation angle of the cutter drum 1 and the output of the potentiometer 12 and the sensor pitch.3. ．． The rotation angle B of the cutter drum 1 from the reference point when the sensor bit 3I is at point B is extracted from the database containing the angle when the sensor bit 3I is on the vertical line OA. Take out the angle A when it is on the OA cotton wire. Then, the calculation control means 16 calculates the angle θ by calculating θ=A−B, and then calculates the cutting depth hI at one end of the cutter drum 1 from the above-mentioned equation 0. Similarly for other sensor bits 3□, cut depth h at the other end of cutter drum 1.
2 calculations are performed. Next, in the calculation control means 16,
The following calculation is performed based on this calculation result. That is, a=j a n-' (hI hz /L)""■
Here, L is the distance between the cutter bits forming the sensor bits 31, 3□.

Then, these calculation results, that is, the cutting depth hI at one end of the cutter drum 1, the cutting depth h2 at the other end, and the inclination angle α of the cutter drum 1 are displayed. In this case, the display of α is 0゜hl when h = h, positive when >hz, h
, <h2, it is negative.

As explained above, according to the present embodiment, due to the action of the six sensor bits 31 and 32 installed on the cutter drum 1 and the potentiometer 12, the cutter drum 1 after the sensor bit 3 touches the ground until it passes the vertical line OA The rotation angle θ can be easily detected, and based on this rotation angle θ, the cutting depths hI and hz can be calculated using the above formula 0, and based on this, h, and the above formula Since the inclination angle of the cutter drum 1 can be calculated and the results of these calculations are displayed, the operator can adjust the vehicle body support means 34 and 35 mentioned above while viewing this by adjusting the vehicle height adjustment controller provided at the rear of the vehicle body. 37 has the advantage that the cutting depth can be easily adjusted.

Incidentally, the rotation direction of the cutter drum 1 can also be reversed to that shown in FIG. In this case, point B is the point where the cutter bit 2A forming the sensor bit 3 leaves the road surface, but the same effect can be obtained by adding an inverting circuit to the output stage of each operational amplifier 13. .

〔Effect of the invention〕

Since the present invention is constructed and functions as described above, according to the present invention, each force sensor detects the point at which the cutter bit at both ends to which the force sensor is attached comes into contact with the road surface or leaves the road surface, and the cutter drum at this time is detected. The rotation angle of the cutter drum can be detected using a rotation angle sensor, and based on these detection results, the cutting depth at both ends of the cutter drum and the cutter diameter can be determined without danger during cutting by the operation of the arithmetic processing display means. It is possible to measure the inclination of the drum and display this result. Therefore, the operator can easily adjust the cutting depth using the vehicle height adjustment controller while looking at this, making it possible to provide an unprecedented and superior cutting depth measuring device for road milling vehicles. .

[Brief explanation of the drawing]

FIG. 1 is a partially omitted front view showing a cutter drum, which is the main part of the first embodiment of the present invention, FIG. 2 is a partially omitted right side view of FIG. 1, and FIG. 3 is a partially omitted side view of FIG. FIG. 4 is an explanatory diagram showing the internal structure of the sensor bit in FIG. 1, and FIG. 5 is an explanatory diagram showing the internal structure of the sensor bit in FIG. FIG. 6 is a block diagram showing the configuration of the circuit section of the embodiment. FIG. 6 is a diagram for explaining the principle of measurement. FIG. Figure 7 (2) is a diagram for explaining the relationship between
) is an explanatory diagram showing the relationship between the output voltage of the potentiometer and the cutter drum, and FIGS. 8 and 9 are explanatory diagrams showing conventional examples. 1...Cutter drum, 2.2A...
Cutter bit, 3. ．． 3. ...Sensor bit consisting of a cutter bit equipped with a force sensor, 11,
111.11□... Load cell as a force sensor, 12... Potentiometer as a rotation angle sensor, 20... Arithmetic processing display means. Patent applicant Tokyo Keiki Co., Ltd.

Claims (1)

[Claims] (1) A cylindrical cutter drum rotatably supported on the abdomen of the vehicle body, and a plurality of cutter bits provided on the outer periphery of the cutter drum almost over the front, the cutter drum having a plurality of cutter bits attached to the cutter drum. A rotation angle sensor that detects the rotation angle of the drum is attached, and a force sensor that electrically detects changes in the force acting on at least one of the cutter bits located at both ends of the cutter drum. and a calculation processing display means for calculating and displaying the cutting depth at both ends of the cutter drum and the inclination of the cutter drum by performing predetermined calculations based on the output signals of the force sensor and the rotation angle sensor. A cutting depth measuring device for road cutting vehicles featuring: