JP4855449B2 - Screed vertical adjustment device for road paving machine - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a screed vertical adjustment device for a road pavement machine, and more particularly to a screed vertical adjustment device for a road pavement machine provided with a lower layer screed and an upper layer screed for spreading a pavement material in two upper and lower layers.

  Conventionally, when a pavement material is spread in two layers on the road in a single pavement operation, a self-propelled road pavement machine equipped with a lower layer screed and an upper layer screed at the rear of the vehicle body is used.

  As shown in FIG. 6, the road pavement machine has a lower hopper 3 mounted on the front portion of the vehicle body 2 that is self-propelled by the crawler 1, and an upper hopper 4 disposed behind the lower hopper 3, In addition, a lower layer conveyor (not shown) and an upper layer conveyor 5 are respectively provided below the lower layer hopper 3 and the upper layer hopper 4. Further, a lower layer screw spreader 6, a lower layer screed 7, an upper layer screw spreader 8, and an upper layer screed 9 are sequentially disposed in the lower rear portion of the vehicle body 2.

  Then, the lower layer pavement material or the upper layer pavement material thrown into the lower layer hopper 3 or the upper layer hopper 4 during the pavement operation is conveyed to the rear of the vehicle body by the lower layer conveyor or the upper layer conveyor 5 and then the lower layer screw spreader 6 or the upper layer screw spreader 8. Is spread on the road and spread by the lower screed 7 or the upper screed 9.

  In the road paving machine, the vertical position of the lower layer screed 7 is appropriately adjusted by a screed vertical adjustment device in order to correspond to the construction thickness of the paving material on the road. A conventional example of the screed vertical adjustment device is shown in FIG. As shown in the figure, the lower screed 7 and the upper screed 9 are connected to and supported by the rear ends of the lower screed arm 7A and the upper screed arm 9A, and the front ends of the lower screed arm 7A and the upper screed arm 9A. The part is connected to a vehicle body front part (not shown) so as to be rotatable up and down.

Further, a cylinder (not shown) that can be extended and contracted is interposed between the lower screed arm 7A and the vehicle body, and the vertical adjustment of the lower screed arm 7A and the lower screed 7 is performed by driving the cylinder to extend and contract. (See, for example, Patent Document 1).
Japanese Patent No. 3548129

  In the screed vertical adjustment device, the lower screed and the upper screed are supported by dedicated screed arms, respectively, so that the number of screed arms increases and the weight increases. Further, since the vertical position of the lower screed is adjusted by driving up and down by the cylinder, it is difficult to accurately adjust the vertical position of the lower screed.

  In view of the above problems, the present applicant has developed a screed vertical adjustment device that supports a lower screed and an upper screed in common by one screed arm, and slides the lower screed up and down with a motor drive system relative to the screed arm. (See Japanese Patent No. 322829). However, according to this method, it is necessary to provide a plurality of screw shafts and motors that also serve as support members on the left and right sides of the lower screed, and to attach many accessory parts such as drive transmission means between the screw shafts.

  In particular, when the weight of the lower screed is increased, the number of screw shafts and accessory parts is increased to increase the support strength accordingly, and the structure becomes large. Therefore, a lighter and more compact screed vertical adjustment device has been a major issue.

  Therefore, there is a technical problem to be solved in order to improve the vertical adjustment accuracy of the lower screed and to realize a lightweight and compact screed vertical adjustment device, and the present invention solves this problem. With the goal.

The present invention has been proposed to achieve the above object, and the invention according to claim 1 is a road pavement machine in which a lower screed is disposed in front of an upper screed supported at the rear end of a screed arm. In the screed vertical adjustment device,
With a screw hole on the upper surface of the holding member for holding the upper surface portion or the lower screed holding member for holding the holding member and the upper screed to hold the lower screed is formed, screwing the lower end portion to the screw hole A screw shaft that rotates and a motor that rotationally drives the screw shaft are provided on the screed arm, and the holding member is supported by a link mechanism provided between the holding member and the screed arm so as to be vertically movable. And a screed vertical adjustment device for a road pavement machine configured to adjust the vertical position of the lower layer screed by rotationally driving the screw shaft.

  According to this configuration, the screw hole is formed in the upper surface portion of the holding member that holds the lower layer screed, and the screw shaft whose lower end is screwed into the screw hole is provided on the screed arm so as to be rotationally driven. Is driven by a motor to adjust the vertical position of the lower screed. At this time, the lower layer screed is adjusted up and down while being stably supported by the link mechanism.

  According to a second aspect of the present invention, there is provided a screed vertical adjustment device for a road pavement machine according to the first aspect, wherein the link mechanism has a pair of upper and lower parallel link members constituting a parallelogram.

  According to this configuration, the holding member can be supported at two upper and lower positions by the pair of upper and lower parallel link members, so that the support strength and stability with respect to the holding member and the lower layer screed are increased.

  According to the first aspect of the present invention, since the lower screed and the upper screed are supported by a common screed arm, the screed arm that exclusively supports the lower screed can be omitted, and a large number of screw shafts and Since there is no need to provide each accessory part, the number of parts can be greatly reduced compared to the conventional example.

  In particular, even when the lower screed is enlarged, the screed vertical adjustment device can be made lighter and more compact. Further, since the lower screed slides up and down by screw driving, the vertical position of the lower screed can be adjusted with high accuracy.

  Since the invention according to claim 2 increases the supporting strength and stability of the lower screed by the link mechanism, in addition to the effect of the invention according to claim 1, the lower screed is further stabilized even when the weight of the lower screed is large. Can be supported.

  The present invention improves the accuracy of vertical adjustment of the lower screed, can cope with the increase in size of the lower screed, and achieves the purpose of realizing the weight reduction of the screed vertical adjustment device. In a screed vertical adjustment device for a road pavement machine in which a lower screed is disposed in front of an upper screed supported on a screw hole is formed on the upper surface portion of the holding member for holding the lower screed or the upper screed, A screw shaft whose lower end is screwed into the screw hole and a motor that rotationally drives the screw shaft are provided in the screed arm, and the holding member is provided between the holding member and the screed arm. It is supported so that it can be moved up and down by the link mechanism, and the vertical position of the lower layer screed can be adjusted by the rotational drive of the screw shaft It was realized by the.

  A preferred embodiment of the present invention will be described below with reference to FIGS. This embodiment is applied to a self-propelled road paving machine in which paving materials are spread in two layers in one up and down in one paving operation, but the basic configuration of the road paving machine excluding the screed vertical adjustment device. Is substantially the same as the conventional example shown in FIG. That is, in the road pavement machine, a lower layer hopper and an upper layer hopper for inputting a pavement material are mounted on a vehicle body, and a lower layer conveyor and an upper layer conveyor are disposed below the lower layer hopper and the upper layer hopper, respectively.

  Further, a lower layer screw spreader, a lower layer screed (a pair of left and right), an upper layer screw spreader, and an upper layer screed are sequentially disposed at the rear portion of the vehicle body. Accordingly, the pavement conveyed to the rear of the vehicle body by the lower layer conveyor or the upper layer conveyor is spread on the road by the lower layer screw spreader or the upper layer screw spreader, and then spread by the lower layer screed or the upper layer screed.

  FIG. 1 shows a screed vertical adjustment device installed in the road paving machine. In the figure, 11A and 11B are a pair of left and right lower screeds, and an upper screed 12 is disposed behind the lower screeds 11A and 11B. The upper screed 12 is supported by a rear end portion of a screed arm (leveling arm) 14 extending rearward on both sides in the width direction of the vehicle body, and the screed arm 14 is provided such that its height can be adjusted by a drive cylinder 13 or the like.

The upper portions of the pair of left and right lower screeds 11A and 11B are supported by a holding member 15. As shown in FIG. 2, the screw hole 16 is formed in the substantially central portion of the holding member 15, but the present invention is not limited to this. For example, the screw hole 16 is formed on the inner surface of the cylindrical member 17 fixed to the holding member 15. Can be engraved. The upper screed 12 can be supported by the holding member 15 by providing the upper screed 12 with the holding member 15.

  The screw hole 16 is screwed with a lower end portion of a screw shaft 18 that functions as a vertical adjustment member, and a sprocket 19 is integrally provided on the upper end portion of the screw shaft 18 as shown in FIG. Yes.

  Further, a rotational drive motor 20 is disposed at a side position corresponding to the sprocket 19, and the motor 20 is installed inside the screed arm 14 (on the right side in FIG. 3). The output shaft of the motor 20 is connected to the sprocket 19 on the screw shaft 18 side via a transmission chain 21.

  Therefore, when the screw shaft 18 is rotated in the normal rotation direction or the reverse rotation direction by driving the motor 20, the holding member 15 and the lower screed 11A, 11B slide upward or downward. In addition, while forming a spherical surface part in the upper intermediate part of the screw shaft 18, a spherical bearing (see reference numeral 23 in FIG. 3) that rotatably holds the spherical surface part can be provided on the screed arm 14 side.

  A bracket 24 is integrally attached slightly ahead of the holding member 15 in the screed arm 14, and the lower screed 11 </ b> A, 11 </ b> B can be moved up and down between the bracket 24 and the side end of the holding member 15. A supporting link mechanism 25 is provided.

  In the present embodiment, the link mechanism 25 has an upper link member 26 and a lower link member 27 that are vertically parallel to each other, and the front end portions of the upper link member 26 and the lower link member 27 are an upper pin 28 fixed to the bracket 24 and Each lower pin 29 is pivotally attached.

  The rear end portions of the upper link member 26 and the lower link member 27 are pivotally attached to the upper pin 30 and the lower pin 31 (see FIGS. 4 and 5) fixed to the front portion of the holding member 15, respectively, and the front side The distance between the upper pin 28 and the lower pin 29 is set to be equal to the distance between the rear upper pin 30 and the lower pin 31. The pins 28 and 30 can be fixed to the inner surface side of the screed arm 14.

  As described above, according to the present embodiment, the lower end portion of the screw shaft 18 is screwed into the screw hole 16 of the holding member 15 that supports the lower screed 11A, 11B, and the upper portion of the screw shaft 18 is rotated to the screed arm 14. Since the screw shaft 18 is driven to rotate in the forward or reverse direction by the motor 20, the lower screeds 11A and 11B held by the holding member 15 are simultaneously adjusted to the desired vertical position.

  Further, since the holding member 15 is supported at the upper and lower portions by the upper link member 26 and the lower link member 27, the supporting strength of the lower layer screeds 11A and 11B is increased. Therefore, even when the lower screed 11A, 11B is heavy, the lower screed 11A, 11B can be stably supported without increasing the number of screw shafts 18.

  As a result, the screed arm dedicated to the lower layer screed 11A, 11B required in the conventional apparatus can be omitted, and it is not necessary to attach a plurality of screw shafts and accessory parts on both sides of the holding member 15. Therefore, the lower layer screed 11A, 11B. Even if the size of the screed is increased, the screed vertical adjustment device as a whole can be significantly reduced in weight and the structure can be made compact.

  Further, since the lower screeds 11A and 11B slide quantitatively up and down according to the number of rotations of the screw shaft 18, the vertical positions of the lower screeds 11A and 11B can be adjusted with high accuracy.

  Further, when a spherical portion is provided in the middle portion of the screw shaft 18 and the spherical portion is rotatably supported by a spherical bearing 23 provided on the screed arm 14, the lower screeds 11A and 11B are vertically moved by the rotation of the screw shaft 18. At the time of adjustment, it is possible to effectively suppress the occurrence of lateral vibration in the lower layer screed 11A, 11B, and the vertical adjustment accuracy of the lower layer screed 11A, 11B can be further improved.

The present invention is Ru can be variously modified without departing from the spirit of the present invention. For example, the output shaft of the motor 20 may be directly connected to the sprocket on the screw shaft 18 side without passing through the transmission chain 21 (FIG. 3). The present invention naturally extends to the modified one.

BRIEF DESCRIPTION OF THE DRAWINGS The whole side view of the screed vertical adjustment apparatus of a road pavement machine which shows one Example of this invention. Explanatory drawing explaining the principal part of the screed vertical adjustment apparatus which concerns on this invention. Explanatory drawing which shows the screw shaft of the screed up-down adjustment apparatus which concerns on this invention, and the attachment structure of a motor. The AA arrow directional view which shows the link mechanism of the screed vertical adjustment apparatus of FIG. The BB line arrow directional view which shows the screed up-and-down adjustment apparatus (one side half part of the center line C of the vehicle width direction) of FIG. The side view which shows the road pavement machine which concerns on a prior art example. Explanatory drawing which shows the screed up-down adjustment apparatus of the road paving machine which concerns on a prior art example.

Explanation of symbols

11A Lower layer screed 11B Lower layer screed 12 Upper layer screed 14 Screed arm 15 Holding member 18 Screw shaft 20 Motor 23 Spherical bearing 24 Bracket 25 Parallel link mechanism 26 Upper link member 27 Lower link member

Claims (2)

In a screed vertical adjustment device for a road pavement machine, in which a lower screed is disposed in front of an upper screed supported at the rear end of a screed arm,
With a screw hole on the upper surface of the holding member for holding the upper surface portion or the lower screed holding member for holding the holding member and the upper screed to hold the lower screed is formed, screwing the lower end portion to the screw hole A screw shaft that rotates and a motor that rotationally drives the screw shaft are provided on the screed arm, and the holding member is supported by a link mechanism provided between the holding member and the screed arm so as to be vertically movable. A screed vertical adjustment device for a road pavement machine, wherein the vertical position of the lower screed can be adjusted by rotationally driving the screw shaft.   2. The screed vertical adjustment device for a road pavement machine according to claim 1, wherein the link mechanism has a pair of upper and lower link members constituting a parallelogram.

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