JP2846256B2 - Pavement thickness measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pavement thickness measuring device for measuring a pavement thickness of an asphalt pavement road or the like, and more particularly to a pavement thickness measurement device for measuring a pavement thickness immediately after laying.

[0002]

2. Description of the Related Art FIG. 4 is a view showing an example of a conventional pavement thickness measuring apparatus using a radar system. In the figure, 10 is an apparatus main body, 20 is a monitor, and 30 is a wheel for moving the apparatus main body. The apparatus body 10 is provided with a transmitter and a receiver for transmitting and receiving electromagnetic waves by a pulse radar method, a transmitting and receiving antenna, and a range finder for measuring a moving distance from rotation of a wheel.

Next, the operation of the conventional apparatus shown in FIG. 4 will be described. Electromagnetic waves are transmitted and received from the device main body 10 in a pulse radar system, and the pavement at that position is determined by the difference in reception time between the electromagnetic waves reflected on the surface of the asphalt layer 100 and the electromagnetic waves reflected on the boundary 300 between the asphalt layer 100 and the roadbed 200. The thickness is measured. By moving the apparatus main body 10, the pavement thickness is repeatedly measured at predetermined intervals as described above, and the line profile of the pavement thickness is displayed on the monitor 20. For example, a data recorder or a printer (both in FIG. (Not shown).

The above-mentioned conventional pavement thickness measuring apparatus is mainly aimed at finding a defective portion of a pavement road which has already been completed and used. On a soft and sticky pavement surface immediately after laying, asphalt is applied to wheels. It is difficult to measure because a large amount of particles are attached or the wheels are buried. However, when paving a road with a construction machine such as an asphalt finisher, it is necessary to proceed with the work while checking at any time whether or not the pavement thickness is laid to a predetermined thickness. Because of this necessity, the present applicants have made an invention (referred to as a prior invention) disclosed in Japanese Patent Publication No. 6-19266, “A device for measuring the thickness of a pavement in an asphalt finisher”. In this prior invention, the wheel 30 is removed from the apparatus main body 10 shown in FIG. 4, and the apparatus main body is directly attached to an asphalt finisher via a traction device (not shown). The measurement can be performed automatically.

However, even with the apparatus according to the prior invention, it is difficult to measure the pavement thickness for a long time during pavement (laying) work or immediately after pavement (laying) (hereinafter, these will be referred to as immediately after laying). is there. That is, since the asphalt immediately after laying has a soft and sticky surface, the contact resistance and ground pressure at which the device body 10 comes into contact with the asphalt surface are reduced as much as possible to prevent asphalt from adhering and to scratch the asphalt surface. However, in the device according to the prior invention, since the device body 10 is merely towed by the asphalt finisher via the towing device, the contact resistance with the pavement surface is large, and the device body 10 Most of its own weight is added to the asphalt surface. In addition, since the apparatus main body 10 is merely towed via the towing apparatus, the vibration caused by the towing is directly applied to the apparatus main body 10. Moreover, the surface temperature of the asphalt immediately after the laying is about 150 ° C., so that the transceiver and the antenna (hereinafter, referred to as the transmitting and receiving unit) housed in the apparatus main body 10 are erroneously operated by the influence of heat. There is a risk of being destroyed. Furthermore, if the temperature difference between the asphalt surface and the contact area thereof is large, asphalt will adhere to the contact area. However, in the apparatus according to the prior invention, the temperature difference between the asphalt surface and the contact area of the apparatus body 10 is large. However, there is a problem that the asphalt adheres to such a large amount.

[0006]

As described above, despite the necessity of the conventional pavement thickness measuring device, there is a problem that it is difficult to measure the pavement thickness immediately after laying for a long time in a stable manner. .

The present invention has been made to solve such a problem, and an object of the present invention is to provide a pavement thickness measuring device capable of stably measuring a pavement thickness immediately after laying for a long time.

[0008]

According to the present invention, there is provided a pavement thickness measuring apparatus, comprising: a sliding body such as a sled attached to the bottom surface of an apparatus main body; and a means for bringing the sliding body into contact with a pavement surface. Most of the weight of the main body is supported by a self-propelled machine through a shock absorbing device such as a spring, and therefore, there is provided means for providing a suspension mechanism for reducing a ground pressure of the slide body in contact with the pavement surface to a desired pressure. And

Further, the sliding body is formed of a synthetic resin having a low friction coefficient.

Further, the sliding body is formed of a metal having good heat conductivity, or further provided with a heater.

[0011]

According to the pavement thickness measuring device of the present invention having the above-described configuration, the problem of asphalt adhesion can be avoided in the measurement of the pavement thickness immediately after laying, and the device can be operated stably. Can be.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing an embodiment of a pavement thickness measuring apparatus according to the present invention. FIG. 1 (A) is a plan view, FIG. 1 (B) is a front view, and FIG. 1 (C) is a side view. In the figure, 1 is an apparatus main body, 2 is a sled portion, 3 is a connecting plate, 11 is a connecting shaft, 12 is a guide pin, and 13 is a grip portion. As shown in FIG.
The pavement thickness measuring apparatus according to the present embodiment has a configuration in which an apparatus main body 1 provided with a transmission / reception unit and a blower (both not shown in FIG. 1) is mounted on a sled unit 2.

That is, the pavement thickness measuring device of this embodiment is
Stop self-propelled in the same way as the prior invention and attach it to a construction machine such as asphalt finisher via a coupling device,
Move with the movement of the construction machine. However, simply attaching and moving to a construction machine such as an asphalt finisher causes a problem that the contact resistance of the contact surface and the ground pressure as described above are large. Therefore, in this embodiment, the apparatus main body 1 is mounted on a sliding body represented by a so-called sled. In the present invention, it goes without saying that the shape and structure of the sled are not limited to those shown in FIG. 1 and that the sled is not limited to a sled.

In this embodiment, the connecting plate 3 and the connecting shaft 11
Thus, a connecting device provided with a suspension mechanism having a structure for suspending the device main body 1 via a spring in the vertical direction in the drawing is configured, and is attached to the construction machine via the connecting device. That is, in FIG. 1, the (a) surface of the connecting plate 3 is a portion directly fixed to a construction machine such as an asphalt finisher.
By inserting the device main body 1 from above and fitting the connection shaft 11 and the guide pin 12 into the respective notches, the device main body 1 is supported with most of its own weight by the connection shaft 11 via the spring. A structure in which the sled portion 2 provided on the bottom surface is brought into contact with the pavement surface can be provided.

That is, as shown in FIGS. 2A and 2B, the connecting shaft 11 in contact with the connecting plate 3 is
When the construction machine moves up and down and the connecting plate 3 moves up and down, the connecting shaft 11 moves up and down the guide hole 15 accordingly. Are connected via a spring mechanism 14, the vertical movement of which is a compression / expansion force of the spring and is not transmitted to the apparatus main body 1, so that the apparatus main body 1 can be moved in the front, rear, left and right directions. Although it is forcibly moved by the movement of the machine, most of its own weight of the apparatus main body 1 is supported by the connecting shaft 11, so that it can be always in contact with the pavement surface with a low ground pressure. , The device body 1 is not broken by vibration or vertical movement due to a step, and the road surface immediately after laying is not damaged. By providing such a connecting device, the problem of ground pressure and the problem of vibration during towing in the prior invention were solved. The connecting device is not limited to those shown in FIGS.
What is necessary is just to provide at least a suspension mechanism capable of reducing the ground pressure and absorbing a vertical shock.

[0016] In addition, even when the sliding body such as a sled slides on the road surface, if the sliding body itself has a large contact resistance or if asphalt easily adheres to the sliding surface, the sliding body immediately after the laying may be used. Pavement thickness measurement becomes difficult. Therefore, in the pavement thickness measuring device of the present invention, a sliding body such as a sled is formed of a synthetic resin having a low friction coefficient or a metal having good heat conductivity. For example, it has been found that Teflon (trade name) has the lowest coefficient of friction among all solids and has no asphalt adhesion. If a sliding body is formed with Teflon, heat resistance, abrasion resistance and sliding properties are good, In addition, a pavement thickness measuring device free from asphalt adhesion can be obtained.

When the sliding body is not formed of the synthetic resin having a low coefficient of friction as described above, the contact resistance is increased mainly due to the temperature difference between the asphalt surface and the sled immediately after the laying as described above, and the adhesion of the asphalt is reduced. Problems arise. That is, as described above, the asphalt surface immediately after laying has a surface temperature of about 150 ° C., and when a sliding body is not formed of a synthetic resin having a low coefficient of friction, if the temperature difference from the sled is large,
A problem arises in that the contact resistance increases and asphalt adheres to the downhill surface of the sled portion 2.
Therefore, in another embodiment of the present invention, a sliding body such as a sled is formed of a metal having good heat conductivity. In this case, by using the connecting device provided with the suspension mechanism as described above, the ground pressure of the sliding body such as a sled can be sufficiently reduced, so that even a relatively soft light alloy such as aluminum can be used. , Sufficient abrasion resistance.

Further, as shown in FIG. 3, a blower 17 is provided so that the transmitting / receiving unit 16 is not mainly cooled as in, for example, JP-A-92-11587, but is blown with cold air onto a high-temperature asphalt surface. The surface is cooled to prevent the adhesion, and a heat insulating wall is formed by the wind pressure to protect the transmitting and receiving unit 16 from high heat.

Further, even if the sled portion 2 is formed of a metal having good thermal conductivity, the sled itself becomes too low due to the outside temperature in a cold region or the like, so that the sled just touches the asphalt surface immediately after laying. It is conceivable that asphalt adheres to the surface. Therefore, in another embodiment of the present invention, a heater is built in the sled portion 2, and the sled portion 2 is heated at a high temperature in a cold region or the like to prevent asphalt from adhering, and has a structure capable of always performing good sliding.

[0020]

As described above, the pavement thickness measuring device of the present invention reduces the contact pressure by the connecting device provided with the suspension mechanism and slides the pavement surface with the sliding body. Because it is made of synthetic resin with low thermal conductivity, or made of metal with good thermal conductivity, it uses a blower or heater to cool the pavement surface immediately after laying or heat the gliding body according to the outside temperature In the measurement of the line profile of the asphalt thickness immediately after laying, there is an effect that a long-term stable measurement can be performed.

[Brief description of the drawings]

FIG. 1 is an external configuration diagram showing an embodiment of a pavement thickness measuring device according to the present invention.

FIG. 2 is a view for explaining a connecting device of the device shown in FIG. 1;

FIG. 3 is a diagram for explaining the internal structure of the device shown in FIG.

FIG. 4 is a view for explaining a conventional pavement thickness measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 2 Sled part 3 Connecting plate 11 Connecting shaft 12 Guide pin 13 Grasping part 14 Spring mechanism 15 Guide hole

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masayuki Aimoto 6-1 Asahimachi, Obu City, Aichi Prefecture Sumitomo Construction Machinery Co., Ltd. Nagoya Plant (56) References JP-A-63-122910 (JP, A) JP-A Hei 5-196447 (JP, A) Fully open 1987-103810 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01B 15/00-15/08 E01C 19/48

Claims (4)

(57) [Claims] An apparatus main body is connected to a self-propelled machine such as a construction machine using a connecting device, and a traveling unit of the self-propelled machine moves the apparatus main body on a pavement surface. In a pavement thickness measuring device that transmits and receives electromagnetic waves to measure a pavement thickness line profile, a means for attaching a sliding body such as a sled to a bottom surface of the apparatus body and making contact with the pavement surface with the sliding body, In the state of use of the apparatus, a suspension mechanism is provided in which most of the weight of the apparatus main body is supported by the self-propelled machine via a shock absorber such as a spring, so that the ground pressure of the sliding body in contact with the pavement surface is reduced to a desired pressure. Means for measuring a pavement thickness. 2. The pavement thickness measuring device according to claim 1, wherein said sliding body is formed of a synthetic resin having a low coefficient of friction. 3. The pavement thickness measuring device according to claim 1, wherein said sliding body is formed of a metal having good thermal conductivity. 4. A pavement thickness measuring device according to claim 3, wherein said sliding body is provided with a heater.