JP7190738B2 - Road milling machine and road milling vehicle - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law Date of sale January 17, 2019 Place of sale Unite Co., Ltd. Osaka Construction Office (2-13-1 Karasaki Nishi, Takatsuki City, Osaka Prefecture) Seller Hanta Machinery Co., Ltd.

TECHNICAL FIELD The present invention relates to a road milling machine for cutting a road surface and a road milling vehicle using the same, and more specifically, the road surface is scraped and loosened by rotating a milling drum having a large number of bits. The present invention relates to a road milling machine and a road milling vehicle equipped with a mechanism for feeding cutting objects to a conveyor.

A road milling machine and a road milling vehicle equipped with a mechanism for scraping the road surface by rotating a milling drum having a large number of bits and feeding the scraped cut material to a conveyor are described in Patent Documents 1 to 7. Various proposals have been made in the past. In these road milling vehicles, the scraped cuttings are fed to a conveyor and loaded onto a co-running vehicle.

The cuttings must be efficiently fed from the cutting drum to the conveyor so that the cuttings do not remain on the road surface.

Conventionally, as described in Patent Document 1, a rubber plate is elastically deformed by using a front cover (7) made of a rubber plate under the front surface of a machine frame (2) that holds a cutter drum (3). So, the cutting material is sent from the machine frame (2) to the conveyor device (12) by eliminating the gap with the road surface.

In Patent Document 2, the frame body (5) has curved cutting edges (9, 12) (bottom plate front edge) on the side of the raking means (6), the cutting edge (12) extending laterally slidable. Therefore, Patent Literature 2 discloses a device that, when waste materials are scattered outside the width, scrapes the waste materials by widening the width.

Patent Document 3 discloses a front cover (6) made of a rubber material or the like attached to a fixed frame (11). Further, Patent Document 3 discloses a front cover (10) attached to the side of the conveyor device (20), and the front cover (10) can be pivoted upward to match the arm (16). It is said that there is

Patent Literature 4 discloses a rubber cover (4a) provided under the front cover (4).

US Pat. No. 5,300,004 discloses a belt shoe (16) that moves up and down.

Patent Literature 6 discloses a front opening/closing member (11a) for adjusting the opening/closing amount of the front gate (10c).

US Pat. No. 5,300,009 discloses a belt shoe (16) that moves up and down.

Japanese Utility Model Publication No. 7-15847 Patent No. 2798312 Patent No. 3169101 Patent No. 3320873 Patent No. 3698267 Patent No. 3949493 Patent No. 4106183

As described in Patent Document 1, when the front cover (7) is made of a rubber plate, when the depth of cutting of the road surface becomes deep, the rubber plate bends too much, and the cutting material is pushed into the machine frame (3) of the cutter drum (3). 2), the loading efficiency of the cut material is lowered.

Patent document 1 discloses that a metal plate is used as the front cover (7) instead of the rubber plate. However, if a metal plate is used and the cutting depth is increased, the metal plate may come into contact with the road surface and be damaged. Japanese Patent Laid-Open No. 2002-200003 does not describe any adjustment of the cutting depth in the case of the front cover (7) using a metal plate.

In Patent Document 1, by pulling open the front cover (7) with a wire rope (15), the powdery waste material (5b) dumped by the sweeper (24) is transferred to the conveyer device (12) together with the cut material. Discloses a mechanism for feeding into. However, the opening and closing of the front cover (7) by means of the wire rope (15) does not contribute to the efficient feeding of the material cut by the cutter drum (3) to the conveyor device (12).

In Patent Document 2, the cutting edges (9, 12) are laterally slidable but fixed in the cutting depth direction. Therefore, even in the device described in Patent Document 2, if the cutting depth is increased, the cutting edges (9, 12) may come into contact with the road surface and be damaged.

In Patent Document 3, the front cover (6) is a rubber plate or the like, and as in Patent Document 1, when the cutting depth is deep, it bends too much, thereby reducing the loading efficiency of the cut material. Further, Patent Document 3 discloses a front cover (10) attached to the side of the conveyor device (20), and the front cover (10) is pivotable upwards, but this 24) is only a mechanism for taking in the powdery waste material (5b) thrown away, and is not a mechanism for dealing with the cutting depth.

Similarly to Patent Document 1, the rubber cover (4a) of Patent Document 4 also bends excessively when the depth of cutting is deep, which lowers the loading efficiency of the cut material.

The belt shoe (16) according to WO 2005/020001 prevents damage to the transport belt of the conveyor means (10) from below and damage to the transport belt by the crushed material loaded, i.e. between the conveyor belt and the cover plate. to prevent damage to the conveyor belt when switching the position of the conveyor belt to another path (Patent Document 5, page 3, lines 39 to 42). It does not increase the loading efficiency of the

In Patent Document 6, by opening and closing a front opening/closing member (11a) and a rear opening/closing member (11b), excavated pieces of earth and sand pass between a rotary cutter (6) and a cover body (10) depending on the excavation depth. (Patent Document 6, paragraph 0053). do not have.

Patent Document 7 only discloses a belt shoe (16) that moves up and down in accordance with the conveying means (10), and does not disclose a technique for improving the loading efficiency of cut objects.

Thus, there is no prior art disclosing a structure of a front cover (hereinafter referred to as "front cover") of the cutting drum that can improve the loading efficiency of the cutting material even at various cutting depths. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a road milling machine and a road milling vehicle with a front cover that can increase the loading efficiency of the material to be cut even at various cutting depths.

In order to solve the above problems, the present invention has the following features. The present invention is a road surface milling machine that scrapes a road surface by rotating a milling drum having a plurality of bits and feeds the scraped material to a conveyor. A drum unit having a discharge port for feeding a cut object, a front cover covering the front surface of the drum unit and having a shape with an open portion corresponding to the discharge port, a front cover raising and lowering means for moving the front cover up and down, and a cutting drum. and cutting depth detection means for detecting the cutting depth.

The front cover raising/lowering means raises/lowers the front cover in conjunction with the cutting depth detected by the cutting depth detector.

The lower portion of the front cover has a bent portion that is bent toward the cutting drum.

The flexure is replaceable.

The conveyor moves up and down in conjunction with the vertical movement of the front cover.

The front cover lifting means is a cylinder attached to the drum unit.

The cutting depth detection means includes a side cover that covers the side surface of the drum unit and a position detection section that detects the position of the side cover.

When the cutting depth detecting means detects a predetermined value as the cutting depth by the cutting drum, the interlocking between the front cover and the cutting depth is started.

The present invention also provides a road milling vehicle capable of adjusting the depth of milling by the milling drum by adjusting the height of the vehicle or by adjusting the height of the milling drum. Equipped with a road milling machine.

According to the present invention, since the front cover moves up and down in conjunction with the cutting depth, the distance between the ground and the lower end of the front cover can be made as narrow as possible even at various cutting depths. Therefore, even at various cutting depths, the cutting material can be prevented from leaking out of the cutting drum, and as a result, the cutting material can be efficiently discharged from the discharge port by the rotation of the cutting drum. , it is possible to increase the efficiency of loading the cut material onto the conveyor.

In addition, since the front cover moves up and down in conjunction with the cutting depth, damage to the front cover can be prevented even at various cutting depths.

Furthermore, the cutting depth is kept constant by interlocking the position of the front cover according to the cutting depth.

By automatically interlocking the position of the front cover according to the cutting depth, a road milling machine and a road milling vehicle that are convenient for the operator are provided.

By providing a bent portion at the bottom of the front cover, the cut material that could not be sent out from the discharge port can be returned to the cutting drum side again, so that the cut material can be loaded on the conveyor again, resulting in cutting. Improve loading efficiency.

By making the bent portion replaceable, it is possible to prevent a decrease in loading efficiency by replacing the worn bent portion with a new one.

By interlocking the conveyor with the vertical movement of the front cover, the conveyor can be arranged at an appropriate position. As a result, the efficiency of loading and transporting the cut material is improved.

If a cylinder is used as the means for raising and lowering the front cover, the front cover can be moved up and down with a sturdy structure.

If the cutting depth detection by the side cover is used, it is possible to reliably detect the cutting depth while preventing the cut material from coming out to the side.

By starting the interlocking of the cutting depth and the front cover when a predetermined value is detected, the operation from the start of cutting to the interlocking of the front cover becomes smooth.

A road milling vehicle using the road milling machine of the present invention has the same effect as described above.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.

FIG. 1(a) is a left side view of the drum unit 10 with the side cover 20 attached. FIG. 1(b) is a front view of the drum unit 10 with the side cover 20 attached. 2A is a left side view of the front cover 30. FIG. FIG. 2B is a front view of the front cover 30. FIG. FIG. 3(a) is a left side view of the conveyor 40. FIG. FIG. 3(b) is a front view of the conveyor 40. FIG. 4 to 8 show the road milling machine 1 with the drum unit 10, the side cover 20, the front cover 30 and the conveyor 40 assembled. FIG. 4(a) is a left side view showing the positional relationship of each component in the road milling machine 1 before cutting. FIG. 4(b) is a front view of the road milling machine 1 showing the positional relationship of each component in the road milling machine 1 before cutting. FIG. 5(a) is a left side view showing the positional relationship of each component in the road milling machine 1 when performing zero point adjustment. FIG. 5(b) is a front view of the road milling machine 1 showing the positional relationship of each component in the road milling machine 1 when performing zero point adjustment. FIG. 6(a) is a left side view showing the positional relationship of each component in the road milling machine 1 at the start of cutting. FIG. 6(b) is a front view of the road milling machine 1 showing the positional relationship of each component in the road milling machine 1 at the start of cutting. FIG. 7(a) is a left side view showing the positional relationship of each component in the road milling machine 1 at the cutting depth a. FIG. 7(b) is a front view of the road milling machine 1 showing the positional relationship of each component in the road milling machine 1 at the cutting depth a. FIG. 8(a) is a left side view showing the positional relationship of each component in the road milling machine 1 at the cutting depth b. FIG. 8(b) is a front view of the road milling machine 1 showing the positional relationship of each component in the road milling machine 1 at the cutting depth b. FIG. 9 is a block diagram showing the main functional configuration of the road milling machine 1. As shown in FIG. FIG. 10 is a flow chart showing the operation of the road milling machine 1 during cutting. FIG. 11 is a front view showing essential parts of a modification of the front cover 30. As shown in FIG.

Hereinafter, configurations of the drum unit 10, the side cover 20, the front cover 30, and the conveyor 40 will be described with reference to FIGS. 1 to 3. FIG. Next, referring to FIGS. 4 to 8, the function and role of each component during cutting will be described. Then, the control flow of the operation of each configuration will be described with reference to FIGS. 9 and 10. FIG.

A road milling machine 1 in one embodiment of the present invention comprises a drum unit 10 , a side cover 20 , a front cover 30 and a conveyor 40 . In this embodiment, it is assumed that the road milling machine 1 is attached to the vehicle body 2 . A vehicle equipped with the road milling machine 1 is called a road milling vehicle.

Vehicle body cylinders 52 are attached to front wheels (not shown) and rear wheels (not shown) of the vehicle body 2 . The vehicle body cylinder 52 allows the vehicle body 2 to move up and down. By vertically moving the vehicle body 2, the drum unit 10 is vertically moved. By vertically moving the drum unit 10, it is possible to adjust the cutting depth.

In this embodiment, an embodiment in which the cutting depth is adjusted by moving the vehicle body 2 up and down is taken as an example, but the present invention is not limited to this. The present invention also includes road milling machines and road milling wheels that adjust the cutting depth by directly raising and lowering the drum unit 10 .

In FIG. 1, a side cover 20 is attached to the drum unit 10. As shown in FIG. In FIG. 1(b), the side cover 20 is indicated by broken lines in order to facilitate understanding of the structure of the drum unit 10. As shown in FIG. A side cover 20 is attached to the drum unit 10 by side cover suspension wires 24 so as to move up and down. The side cover 20 is moved up and down by the side cover suspension wire 24, but is lowered by the gravity of the side cover 20 (but not limited). The wire winding type potentiometer 21 always pulls the potentiometer wire (not shown) in a winding direction by a spring (not shown). The potentiometer wire is attached to the upper end of the side cover 20 so as to be slightly pulled out. A wire-wound potentiometer 21 can detect the position of the side cover 20 . Note that the side cover suspension wire 24 and the potentiometer wire may also be used.

The drum unit 10 includes a cutting drum 11 , a number of bits 12 , a drum cover 13 and a discharge port 14 . The cutting drum 11 is rotatably held clockwise in FIG. 1(b) by a rotary drive unit (not shown). Bits 12 are mounted, for example spirally, around milling drum 11 . The bit 12 is made of a hard material so that it can scrape the road surface. The bit is also called a chisel. Needless to say, any known structure can be used as the structure of the cutting drum 11 having a plurality of bits 12 .

The drum cover 13 is a frame for enclosing the cutting drum 11 . The front side of the drum cover 13 (the left side in FIG. 1(b)) is in the shape of an open duct so that a discharge port 14 is formed.

As the cutting drum 11 rotates, a large number of bits 12 cut the road surface. The road surface scraped by the bit 12 is loosened as the bit 12 rotates, sent toward the outlet 14 by centrifugal force, and loaded onto the conveyor 40 .

In FIG. 1(b), a back cover is also shown on the right side of the cutting drum 11 in the drawing, but since it is not directly related to the present invention, description of the back cover is omitted.

In FIG. 2 , the front cover 30 includes a pair of left and right hook frames 31 and a pair of left and right front cover upper and lower cylinders 32 . The front cover 30 is mainly made of a metal plate. The front cover 30 has a shape with an open portion corresponding to the discharge port 14 . The lower portion of the front cover 30 has a bent portion 36 bent toward the cutting drum 11 (inward). At the lower end of the front cover 30, a horizontally long steel plate 35 that spans the left and right of FIG. The steel plate 35 is a part that can be replaced when worn, and is a member that constitutes the bent portion 36 .

The hooking frame 31 is a frame on which the suspending shaft 44 of the conveyor 40 can be hooked. Note that the shape of the hanging frame 31 is not limited to the illustrated shape as long as the hanging shaft 44 can be hung.

The front cover vertical cylinder 32 is a hydraulic cylinder or the like and is attached to the drum unit 10 . The front cover 30 can be moved up and down by extending and contracting the front cover vertical cylinder 32 . It should be noted that any mechanism for moving the front cover 32 up and down is not limited to the front cover vertical cylinder 32, and the front cover 32 may be moved up and down by wire winding, a ball screw, or the like. That is, in the present invention, it is sufficient that front cover lifting means for moving the front cover up and down is provided.

In the embodiment shown in FIG. 2, the front cover vertical cylinder 32 incorporates a sensor capable of detecting the amount of expansion and contraction of the cylinder. However, a cylinder that does not incorporate such a sensor may be used as the front cover up/down cylinder 32 . In that case, as shown in FIG. 9, a front cover potentiometer 33 may be provided so that the position of the front cover 30 can be detected. Therefore, it is sufficient that a cylinder for moving the front cover 30 up and down and a position detection section for detecting the position of the front cover 30 are provided. Note that, regarding other configurations as well, the position described as a potentiometer in this specification is merely an example of the position detection unit, and the position detection of the present invention is not limited to that performed by the potentiometer. For example, the position detector that detects the position of the side cover 20 is not limited to the wire winding type potentiometer 21 and the side cover potentiometer 22 .

In FIG. 3, conveyor 40 has a mechanism for rotating conveyor belt 45 . Since the mechanism is well-known, detailed description is omitted. The conveyor 40 has a belt receiving portion 46 at its lower portion. The belt receiving portion 46 prevents the conveyor belt 45 from being damaged by preventing the conveyor belt 45 from coming into contact with the road surface. The conveyor 40 has a pair of left and right hanging shafts 44 at its left and right upper ends. The suspension shaft 44 is a support shaft that can be hooked on the hook frame 31 .

A suspension wire 43 is attached to each of the suspension shafts 44 . The opposite end (not shown) of the conveyor 40 is attached to the vehicle body 2 so as to be able to swing, so that the suspension wire 43 is wound up or fed out so that the conveyor 40 can be moved up and down.

The mechanism for winding or unwinding the suspension wire 43 is not particularly limiting of the invention, but an example is provided here. A conveyor vertical cylinder 41 and pulleys 41a to 41c are attached to the drum unit 10. As shown in FIG. In FIG. 3, the suspension wire 43 on the right side of FIG. It is connected with the hanging shaft 44 . On the other hand, the suspension wire 43 on the left side of FIG. It is connected with the hanging shaft 44 .

In the road milling machine 1 of this embodiment, the cutting depth is measured by the amount of vertical movement of the side cover 20 . A method for measuring the cutting depth will be described with reference to FIGS. 4 to 8, 9 and 10. FIG.

When the vehicle is moving before starting cutting, as shown in FIG. 4, the height of the cutting drum 11 is adjusted by the vehicle body cylinder 52 so that the lower end of the bit 12 is positioned above the ground GL. there is The lower end of the side cover 20 is lower than the lower end of the bit 12 before cutting. However, the side cover 20 may be lifted up during movement.

When aligning the cutting positions, the bit 12 and the ground GL are kept at a certain interval (for example, 50 mm) or more. At this time, the side cover 20 is suspended by the side cover suspension wire 24 so that the bit 12 and the ground GL can be visually recognized.

After the cutting position is determined in this manner, the operator operates the vehicle body up/down switch 53 (not shown in FIGS. 4 to 8) to drive the vehicle body cylinder 52, thereby cutting the bit 12 and the ground GL. lower the drum unit 10 until the At this time, the cutting drum 11 is rotated. Thereafter, the side cover 20 is manually lowered until the side cover suspension wire 24 is loosened, and the side cover 20 is brought into contact with the ground GL. That is, the tip of the bit 12 and the bottom surface of the side cover are aligned (Fig. 5 and S101). After lowering the side cover 20 to the ground GL, which is the lower end, the drum unit 10 may be lowered until the bit 12 and the ground GL come into contact with each other for alignment. The state in FIG. 5 is a cutting depth of 0 (mm), and this point is called a zero point.

Assuming that the position signal of the side cover potentiometer 22 (or the wire winding type potentiometer 21; the same shall apply hereinafter) at the zero point represents a cutting depth of 0, the operator operates the cutting depth operation panel 51 to turn on the controller 50 stores the position signal of the side cover potentiometer 22 at the zero point (S102). At this time, the operator is presented with a display showing that the cutting depth is zero. Also, this zero point setting is performed each time construction is performed.

By storing the position signal of the side cover potentiometer 22 at the zero point in the controller 50 in this way, the controller 50 can compare the position signal of the side cover potentiometer 22 with the position signal at the zero point. , it becomes possible to detect the cutting depth.

For example, as shown in FIG. 7, when cutting is performed to a cutting depth a, the side cover suspension wire 24 is shortened by the cutting depth a. By comparing the position signal at , the controller 50 can recognize that the cutting depth is a. The same is true for the cutting depth b in FIG.

Next, the operation after zero point adjustment will be described.

When starting cutting, the operator operates the front cover up/down switch 34 and the conveyor up/down switch 42 to lower the conveyor 40 and the front cover 30 to their lower limits (FIG. 6: S103). When the conveyor 40 and the front cover 30 are lowered to their lower limits, it is assumed here that the height from the ground GL to the lower end of the front cover 30 is a (mm), as shown in FIG. Note that a is usually a value relating to the minimum cutting depth of the road surface (for example, 50 mm), but in the present invention, a is a value of 0 or more, including 0.

When the conveyor 40 and the front cover 30 are lowered to the lower limit, the controller 50 turns off the conveyor vertical cylinder 41 so as not to drive (S104). As a result, the conveyor 40 is in a state of being entrusted to the hooking frame 31, so that the conveyor 40 also moves up and down in conjunction with the vertical movement of the front cover 30.例文帳に追加

The controller 50 stores the position signal of the front cover potentiometer 33 in the state of S104 as a signal corresponding to the cutting depth a (S105).

Next, the operator inputs the desired cutting depth to be executed (S106). For example, assume that a cutting depth b (mm) (b≧a) is input. After entering the cutting depth, cutting starts. Specifically, the operator rotates the cutting drum 11 using a cutting drum rotation switch (not shown) and lowers the car body cylinder 52 using the car body up/down switch 53 , so that the cutting drum 11 can rotate the road surface. to start cutting. Note that the operator causes the vehicle to move forward as appropriate.

A position signal from the side cover potentiometer 22 is input to the controller 50 during cutting. A position signal from the side cover potentiometer 22 allows the controller 50 to measure the current cutting depth (S107).

Then, the controller 50 determines whether or not the current cutting depth is the desired cutting depth b (S110). , the measurement of the cutting depth is continued, and if different, a signal for extending and retracting the vehicle cylinder 52 is output according to the difference, and the vehicle cylinder 52 is extended and retracted (S111). As a result, the vehicle cylinder 52 is controlled so as to obtain the desired cutting depth, so that the cutting drum 11 can continue cutting at the desired cutting depth. Here, the controller 50 automatically controls the cutting depth by the control of S110 and S111. You may make it adjust the cylinder 52 for vehicles so that it may become. Once the desired cutting depth is reached, the operator manually adjusts the cutting depth. You may make it adjust the height.

In parallel with the operations of S110 and S111, the controller 50 performs the operations of S108 and S109.

The controller 50 determines whether the current cutting depth is greater than or equal to a (S108). If the cutting depth is less than a, there is still a gap between the ground GL and the lower end of the front cover 30 . Therefore, when the cutting depth is less than a, the front cover 30 still does not contact the ground GL and is damaged, so the controller 50 continues digging.

In S108, when the cutting depth is a or more (FIG. 7), that is, when the front cover 30 is moved to the lower limit, the predetermined value corresponding to the height between the lower end and the ground GL is When the cutting depth is detected, there is no gap between the ground GL and the lower end of the front cover 30. Therefore, when cutting further, the front cover 30 must be moved upward. may come into contact with the ground GL and be damaged. Therefore, the controller 50 outputs a telescopic signal for controlling the front cover vertical cylinder 32 so that the position signal of the front cover potentiometer 33 is the same as the current cutting depth (S109). Here, the corresponding value is used because the cutting depth does not have to completely match the height a, and when the cutting depth reaches a value within a predetermined range, the front This is to include the meaning of starting interlocking between the cover 30 and the cutting depth. That is, it means that the interlocking may be started when the cutting depth reaches a predetermined value "ac (mm) (here, c≧0)".

By the operation of S109, the lower end of the front cover 30 is aligned with the ground GL, so the front cover 30 is not damaged. Moreover, since there is no gap between the ground GL and the lower end of the front cover 30, the cutting material is efficiently sent to the conveyor 40 without leaking to the outside.

Although not shown, if the current cutting depth becomes smaller than a after S109, the controller 50 controls the front cover vertical cylinder 32 so that the position signal of the front cover potentiometer indicates the cutting depth. Lower the front cover 30 to the lower limit so that it points to a.

By placing the conveyor 40 on the front cover 30, the suspension wire 43 is bent, and the conveyor 40 moves up and down in conjunction with the movement of the front cover 30, as shown in FIGS. In FIGS. 7 and 8, the suspension wire 43 has a double wavy line, which means that the suspension wire 43 has room to bend.

The current cutting depth measured by the side cover potentiometer 22 is constantly fluctuating according to the road surface condition. , in the vicinity of the desired cutting depth b (FIG. 8).

According to this embodiment, the front cover 30 is controlled to move up and down, and interlocks with the current cutting depth so as to minimize the gap between the lower end of the front cover 30 and the ground GL. Thus, the position of the front cover 30 is controlled. Therefore, since the position of the front cover 30 changes according to the cutting depth, damage to the front cover 30 is prevented, and leakage of the cut material from the drum unit 10 is prevented, thereby improving loading efficiency of the cut material. do.

Also, if the position of the front cover 30 does not move in accordance with the cutting depth, even if the front cover 30 is not damaged, the front cover 30 may rattle and the cutting depth may not be constant. There is However, as in this embodiment, the position of the front cover 30 is interlocked according to the cutting depth, so that the cutting depth is kept constant.

It would be difficult for the operator to try to operate the front cover 30 while visually checking the position of the front cover 30 . In this embodiment, the position of the front cover 30 automatically moves up and down in conjunction with the cutting depth, making the road milling machine 1 user-friendly for the operator.

Although the front cover 30 is linked with the cutting depth, manual operation by the operator is not excluded at all. It goes without saying that the front cover 30 may be moved according to the switch operation by the operator.

In this embodiment, by entrusting the conveyor 40 to the front cover 30 , the conveyor 40 including the belt receiving portion 46 moves up and down in conjunction with the front cover 30 . As a result, even if the position of the conveyor 40 is not controlled, the position of the conveyor 40 can be reliably arranged in an appropriate position according to the cutting depth, thereby improving the efficiency of loading and transporting cut objects. It will be done. It should be noted that placing the conveyor 40 on the front cover 30 means placing the load of the conveyor 40 on the front cover 30 and moving the conveyor 40 up and down in conjunction with the vertical movement of the front cover 30 .

However, the present invention does not exclude a configuration in which the position of the conveyor 40 is adjusted in conjunction with the cutting depth. Of course, it goes without saying that the conveyor 40 may also be controlled in conjunction with the cutting depth. For example, the conveyor 40 and the front cover 30 can be interlocked by controlling the conveyor vertical cylinder 41 to move up and down based on a signal for moving the front cover 30 up and down. Also, other interlocking methods may be used.

It should be noted that the bent portion 36 at the lower end of the front cover 30 is not limited to the shape of a bent plate. As shown in FIG. 11, at the lower end of the front cover 30, the steel plate portion 35 is attached with bolts 35a or the like so as to be inclined toward the cutting drum 11, and as a result, the lower end of the front cover 30 is bent. Such a case is also included in the bent portion 36 at the lower end of the front cover 30 .

The cut material scraped off by the cutting drum 11 is scraped forward, but the cut material that has not reached the discharge port 14 is moved toward the cutting drum 11 by the bent portion 36 at the lower end of the front cover 30. It will slide down. Therefore, the returned cut material is scraped out to the outlet 14 side by the centrifugal force of the cutting drum 11 . Therefore, the presence of the bent portion 36 also improves the loading efficiency of the cut material.

The bent portion 36 is preferably made of a wear-resistant member, and is not limited to being replaceable. However, by making the bent portion 36 replaceable, it becomes possible to perform maintenance when worn.

In the above embodiment, the position of the side cover 20 is used to detect the cutting depth. The present invention also includes an invention in which the position of the front cover 30 is adjusted so as to directly measure the depth of cut using a sensor or device and interlock with the measured depth of cut. That is, in the present invention, it is sufficient to have a cutting depth detection means for detecting the cutting depth by the cutting drum 11, and an example of the cutting depth detection means is the side cover 20 and the wire winding type potentiometer (or , side cover potentiometer 22).

In the above embodiment, the cutting depth is adjusted by adjusting the height of the vehicle. It may be an adjusting device. In that case, the present invention can be implemented by controlling a mechanism for moving the drum unit 10 up and down in the operation in S111.

In the above-described embodiment, the configuration in which the bent portion 36 of the front cover 30 is provided is shown. It is neither mandatory nor a configuration.

Although the present invention has been described in detail, the foregoing description is merely illustrative of the invention in all respects and is not intended to limit its scope. It goes without saying that various modifications and variations can be made without departing from the scope of the invention.

INDUSTRIAL APPLICABILITY The present invention is a road milling machine and a road milling vehicle, and is industrially applicable.

Reference Signs List 1 road milling machine 2 vehicle body 10 drum unit 11 milling drum 12 bit 13 drum cover 14 discharge port 20 side cover 21 wire winding type potentiometer 22 side cover potentiometer 24 side cover suspension wire 30 front cover 31 hook frame 32 front cover vertical cylinder 33 Front cover potentiometer 34 Front cover up/down switch 35 Rope plate 35a Bolt 36 Bending part 40 Conveyor 41 Conveyor up/down cylinder 41a, 41b, 41c Pulley 42 Conveyor up/down switch 43 Suspension wire 44 Suspension shaft 45 Conveyor belt 46 Belt receiver 50 Controller 51 cutting depth operation panel 52 vehicle body cylinder 53 vehicle body vertical switch

Claims (7)

A road milling machine that scrapes the road surface by rotating a milling drum having a plurality of bits and feeds the scraped cut material to a conveyor,
a drum unit rotatably holding the cutting drum and having an outlet for feeding cuttings to the conveyor;
a front cover covering the front surface of the drum unit and having an open shape at a portion corresponding to the discharge port;
front cover lifting means for moving the front cover up and down;
and cutting depth detection means for detecting the cutting depth by the cutting drum,
The front cover lifting means moves the front cover up and down in conjunction with the cutting depth detected by the cutting depth detection unit ,
When the cutting depth detection means detects a predetermined value as the cutting depth by the cutting drum, the interlocking between the front cover and the cutting depth is started . cutting machine. 2. The road milling machine according to claim 1, wherein a lower portion of said front cover has a bent portion bent toward said cutting drum. 3. The road milling machine according to claim 2, characterized in that said bend is replaceable. The road milling machine according to any one of claims 1 to 3, wherein the conveyor moves up and down in conjunction with the vertical movement of the front cover. The road milling machine according to any one of claims 1 to 4, wherein said front cover vertical means is a cylinder attached to said drum unit. The cutting depth detection means is
a side cover covering the side surface of the drum unit;
The road milling machine according to any one of claims 1 to 5, further comprising a position detection unit for detecting the position of the side cover. A road milling vehicle capable of adjusting the depth of milling by the milling drum by adjusting the height of the vehicle or by adjusting the height of the milling drum,
A road milling vehicle, characterized in that it comprises a road milling machine according to any one of claims 1 to 6 .

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