Abstract:
A laser level detection system which detects a reference plane of laser at an arbitrary position includes a plurality of level detection units and an operation unit which displays a detection result of each of the level detection units and can operate each of the level detection units, and the laser level detection unit, which has detected the reference plane of the laser, outputs the detection result and an own identification signal of the level detection unit, and the operation unit displays the detection result and a receiving result of the identification signal of the level detection unit.

Description:
BACKGROUND  
       [0001]     The present invention relates to a laser level detection system that a level detection device is attached to a bucket of a construction vehicle such as a shovel car, so as to detect criterial laser light by the level detection device, and display the information of the level detection device onto a display device disposed in the operating room of the construction vehicle.  
         [0002]     There has been known a laser light detection and operation device for a construction machine that a level sensor is attached to a pole extending upward from a blade of bulldozer, so as to receive laser light of a rotation laser device with the level sensor, and display the difference from the appropriate height onto a remote display based on the light-receiving position of level sensor (reference to JP-H09-257472A).  
         [0003]     In the above laser light detection and operation device for a construction machine, the height from a ground of a predetermined place to the reference plane of rotation laser device is interrelated with the height from the edge of blade to the light-receiving section, so ground leveling as planed can be performed if a land forming operation is performed to receive the laser light at a predetermined height position of the light-receiving section of level sensor.  
         [0004]     However, in the laser light detection and operation device for a construction machine, if there is a plurality of ground leveling places, each having a different height position, the attachment position of level sensor (level detection device) has to be changed in accordance with each of the ground leveling places. Accordingly, it is very onerous to change the attachment position of the level sensor.  
       SUMMARY  
       [0005]     Therefore, the present invention has been made in view of the aforementioned circumstance, and an object of the present invention is to provide a laser level detection system no need to change an attachment position of a laser level detection device when leveling a plurality of places, each having different height.  
         [0006]     In order to achieve the above object, a first aspect of the present invention is directed to a laser level detection system which detects a reference plane of laser at an arbitrary position, comprising: a plurality of level detection units; and an operation unit which displays a detection result of each of the level detection units and can operate each of the level detection units, wherein the laser level detection unit, which has detected the reference plane of the laser, outputs the detection result and an own identification signal of the level detection unit, and wherein the operation unit displays the detection result and a receiving result of the identification signal of the level detection unit.  
         [0007]     The following (1) to (5) are preferred embodiments of the laser level detection system according to the present invention. Any combinations of (1) to (5) are also preferred embodiments of the laser level detection system according to the present invention, unless any contradiction occurs.  
         [0008]     (1) Any one of the plurality of level detection units is selected by the operation unit, and the operation unit displays the detection result and the receiving result of the selected laser level detection unit.  
         [0009]     (2) The plurality of laser level detection units is disposed in an up and down direction.  
         [0010]     (3) The level detection unit disposed in a site which requires the detection result is selected by the operation unit, and the operation unit displays the detection result and the receiving result of the selected level detection unit.  
         [0011]     (4) The plurality of level detection units and the operation unit are the same units, each having the same function and a display section, when the unit is set to master by master/slave switching operation, the unit can be used as the operation unit, and the unit is set to slave by the master/slave switching operation, the unit can be used as the level detection unit.  
         [0012]     (5) When at least two units are set to the master by the master/slave switching operation, each of the units can be switched to a mode which only displays the detection result or a mode which has an operation function and displays the detection result.  
         [0013]     According to the present invention, it is not necessary to change an attachment position of laser level detection device when leveling a plurality of lands each having different height. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is an explanation view showing a structure of laser level detection system according to the present invention.  
         [0015]      FIG. 2  is an explanation view illustrating a structure of level detection unit of the laser level detection system shown in  FIG. 1 .  
         [0016]      FIG. 3  is a front view illustrating the outer appearance of level detection unit.  
         [0017]      FIG. 4  is a block diagram showing a structure of signal processing system of the level detection unit of  FIG. 3 .  
         [0018]      FIG. 5  is a block diagram showing a structure of signal processing system of an operation unit.  
         [0019]      FIG. 6  is a schematic diagram showing when paving a base material, covering material and backfill material on a bulldozed ground.  
         [0020]      FIG. 7  is an explanation view showing a bulldozer of a second embodiment.  
         [0021]      FIG. 8  is an explanation view illustrating a structure of laser level detection system of a third embodiment. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The scope of the present invention, however, is not limited to these embodiments. Within the scope of the present invention, any structure and material described below can be appropriately modified.  
         [0000]     First Embodiment  
         [0023]      FIG. 1  shows a laser level detection system. The laser level detection system comprises a rotation laser device  11  disposed in a predetermined position of land forming ground via a tripod  10 , a level detection device  20  attached to an arm  13  of a hydraulic shovel car (construction vehicle)  12  and an operation unit (operation unit for remote operation)  60  disposed in an operating room  14  of the hydraulic shovel car  12 . A bucket (work device)  15  is swingablly mounted on the leading end of the arm  13  of the hydraulic shovel car  12 , and the arm  13  is mounted on a leading end portion of a boom  16 . If a boom cylinder  17  and an arm cylinder (not shown) are driven, the boom  16  and the arm  13  operate to move the bucket  15  up and down and back and forth, and if a bucket cylinder (not shown) is driven, the bucket  15  swings.  
         [0024]     The rotation laser device  11  emits laser light P, and rotates the laser light P about a vertical axis line J to form a reference plane.  
         [0025]     The level detection device  20  comprises three level detection units  21 ,  31 ,  41  as shown in  FIG. 2 . These three level detection units  21 ,  31 ,  41  are detachably attached by a magnet along the longitudinal direction of the arm  13 .  
         [0026]     The level detection unit  21  is provided with a light-receiving section  22  for receiving the laser light P disposed in one side surface of a body  21 A along the up and down direction thereof. The front surface of the body  21 A is provided with a display section  23 . The display section  23  is provided with a light-emitting diode  24  which indicates downside when the site (position) of light-receiving section  22  for receiving the laser light P is above the central position (reference position), a light-receiving diode  25  which indicates upside when the site is below the central position (reference position), a light-emitting diode  26  which displays that the site (position) of light-receiving section  22  for receiving the laser light P is the central position, and a liquid crystal display portion  27  which analog-displays the difference between the site of light-receiving section  22  for receiving the laser light P and the central position.  
         [0027]     Other level detection units  31 ,  41  have the same structure as the level detection unit  21 ; thus, the explanation thereof is omitted.  
         [0028]      FIG. 4  is a block diagram showing a structure of signal processing system of the level detection unit  21 . The light-receiving section  22  comprises a light-receiving element group that N-light receiving elements such as photodiode are disposed upward and downward at a predetermined interval. The light-receiving signal of each of the light-receiving elements is amplified by an analog circuit section  50  for each of the light-receiving elements. Reference number  51  denotes a digital converter which converts the light-receiving signal amplified by the analogue circuit section into a digital signal, and reference number  52  denotes an arithmetic processor which obtains the difference between the position of light-receiving element (site of light-receiving section  22 ) positioned in the central position of the laser light (central position of beam) received by the light-receiving section  22 , and the central position of the light-receiving section  22  (reference position), based on the digital signal of each of the light-receiving elements converted by the digital converter.  
         [0029]     The arithmetic processor  52  illuminates the light-emitting diodes  24 - 26  corresponding to the difference between the central position of laser light P and the reference position, displays onto the liquid crystal portion  27  the analog display according to the difference, and also sounds a buzzer  54  corresponding to the difference.  
         [0030]     Reference number  55  is a wireless device which wirelessly sends the data of the difference calculated by the arithmetic processor  52  and an ID code to the operation unit  60 , and also receives a signal from the operation unit  60 . Reference number  56  is an operation button which changes accuracy for obtaining the central position of the laser light, and also changes the reference position.  
         [0031]     The signal processing system of other level detection units  31 ,  41  is the same as the level detection unit  21 ; thus, the explanation thereof is omitted.  
         [0032]      FIG. 5  is a block diagram illustrating a structure of signal processing system of the operation unit  60 . Reference number  61  denotes a wireless device which performs sending and receiving with the wireless device  55  of each of the level detection units  21 ,  31 ,  41 . Reference number  62  denotes a display section which displays the difference calculated by the arithmetic processor  52  of each of the level detection units  21 ,  31 ,  41 . The display section  62  similar to the display section of the level detection unit  21  comprises a light-emitting diode  62 A which indicates downside, a light-emitting diode  62 B which indicate upside, a light-emitting diode  62 C which displays that the light-receiving position of laser light P is the central position, and a liquid crystal display portion  62 D which displays the difference between the light-receiving position for receiving the laser light P and the central position.  
         [0033]     Reference number  63  denotes an arithmetic processor which controls the displaying of the display section  62  and sounds a buzzer  46 , based on the data received by the wireless device  61 . Reference number  65  denotes an operation button which changes accuracy for obtaining the central position of the laser light of each of the level detection devices  21 ,  31 ,  41 .  
         [0034]     In addition, a desired level detection unit  21 ,  31  or  41  can be powered off or can be switched to a power-saving mode by the operation of the operation button  65 .  
         [0035]     In this embodiment, a level detection unit having the same structure as the level detection unit  21  is used as the operation unit  60 . A maser/slave switch (not show) is provided in the level detection unit. If the level detection unit is set as master by the master/slave switch, the level detection unit functions as the operation unit. Also, if the level detection device is set as slave, the level detection unit functions as the level detection unit.  
         [0036]     In addition, a mode switch (not shown) is provided. When the master is set, a display mode for displaying only the above difference onto the display section  62  and an operation mode are switchable by the operation of the mode switch. The operation mode can conduct the operation by the operation button and has a function which displays the above difference onto the display section  62 .  
         [0037]     In this case, the operation unit is set to the operation mode.  
         [0000]     Operation  
         [0038]     Next, the operation of laser level detection system having the above structure is explained.  
         [0039]     At first, the rotation laser device  11  is positioned in a predetermined position of land forming ground via the tripod  10  as shown in  FIG. 1 . The rotation laser device  11  emits the laser light P and rotates the laser light P about the vertical axis line J to form a reference plane.  
         [0040]     Next, the level detection unit  21  is attached to the arm  13  of the hydraulic shovel car  12  such that the laser light is illuminated onto the reference position (central position) of the light-receiving section  22  of the level detection unit  21 , while bringing the blade of bucket  15  of the hydraulic shovel car  12  into contact with a ground S of operation depth. In this case, a part of ground S is previously measured and dug at predetermined depth.  
         [0041]     The level detection unit  21  is attached by a strong magnet (not shown) disposed in the body  21 A.  
         [0042]     By the way, in case of improving a road, the height of road shoulder and the height of road surface are different, respectively, and it is necessary to control these height. Accordingly, the level detection units  21 ,  31 ,  41  are attached according to these height.  
         [0043]     For example, as shown in  FIG. 6 , when performing the operation for each of a base material K 1  such as gravel, a covering material K 2  such as sand covered for disposing a clay pipe or the like, and a backfill material K 3  such as soil, each of the level detection units  21 ,  31 ,  41  is attached as described above corresponding to each of the depths. For example, the reference position of the level detection unit  21  is matched with the depth H 1  of the base material K 1  to attach the level detection unit  21  to the arm  13  of the hydraulic shovel car  12 , the reference position of the level detection unit  31  is matched with the depth H 2  of covering member K 2  to attach the level detection unit  31  to the arm  13  of the hydraulic shovel car  12 , and the reference position of level detection unit  41  is matched with the depth H 3  of the backfill material K 3  to attach the level detection unit  41  to the arm  13  of the hydraulic shovel car  12 .  
         [0044]     In this case, materials having the same height as the base material K 1  and the covering material K 2 , respectively, are previously prepared, these materials are positioned onto the ground S to bring the blade of the bucket  15  into contact with the material, and the level detection units  31 ,  41  are attached as described above.  
         [0045]     Next, an operator selects the level detection unit  21  by operating the operation button  65  of the operation unit  60 . By this selection, the operation unit  60  receives only the data sent from the level detection unit  21 .  
         [0046]     In addition, each of the unused level detection units  31 ,  41  is powered off or switched to the power-saving mode by operating the operation button  65  of the operation unit  60 . Thereby, the buttery drain of the level detection units  31 ,  41  can be minimized; thus, the interruption of operation by changing the buttery can be reduced as much as possible.  
         [0047]     If the light-receiving section  22  receives the laser light P emitted from the rotation laser device  11 , the level detection unit  21  wirelessly sends to the operation unit  60  the data of the difference between the position of light-receiving element of the light-receiving section  22 , which is the central position of the laser light P, and the reference position of right-receiving section  22 , and the ID code of the level detection unit  21 .  
         [0048]     If the wireless device  61  receives the data sent from the level detection unit  21 , the operation unit  60  controls the display of the display section  62  based on the received data, i.e., the difference between the light receiving position of the light-receiving section  22  of the level detection unit  21  and the reference position of the light-receiving section  22 . For example, if the position of light-receiving section  22  for receiving the laser light P is above the reference position of the light-receiving section  22 , the light-emitting diode  62 A of operation unit  60  which indicates downside lights up.  
         [0049]     Similarly, if the position of light-receiving section  22  for receiving the laser light P is below the reference position of light-receiving section  22 , the light-emitting diode  62 B of the operation unit  60  which indicates upside lights up, and if the position of light-receiving section  22  for receiving the laser light P is the reference position, the light-emitting diode  62 C lights up. The difference between the light-receiving position for receiving the laser light P and the reference position is analogue-displayed onto the liquid crystal display section  62 D.  
         [0050]     The operator observes the display section  62  of the operation unit  60  to recognize predetermined depth H 1  for digging in the ground. Therefore, the ground can be absolutely bulldozed at predetermined height.  
         [0051]     Next, when paving the base material K 1 , the operator operates the operation button  65  of the operation unit  60  to select the level detection unit  31 . By this selection, the operation unit  60  receives only the data sent from the level detection unit  31 . As described above, the operator observes the display section  62  of the operation unit  60  to recognize predetermined depth H 2  for paving the base material K 1 . Accordingly the base material K 1  can be paved to the predetermined depth H 2 . In addition, when paving the covering material K 2 , the operator operates the operation button  65  of operation unit  60  to select the level detection unit  41  as described above, and the operator observes the display section  62  of the operation unit  60  to recognize predetermined depth H 3  for paving the covering material K 2 . Accordingly, the covering material K 2  can be paved to the predetermined depth H 3 .  
         [0052]     As just described, the operator can control a plurality of height by observing the display section  62  of the display unit  60 . Therefore, it is not necessary for the operator to change the height of rotation laser device  11  and the attachment height of level detection units  21 ,  31 ,  41 . Thus, the operation time can be significantly reduced.  
         [0053]     In the present embodiment, the sending and receiving between the level detection units  21 ,  31 ,  41  and the operation unit  60  is conducted by wireless communication; thus, multiplex communication can be performed. Accordingly, the accuracy for obtaining the central position of laser light can be changed and also the mode of each of the level detection units  21 ,  31 ,  41  for changing the reference position can be changed in a short time.  
         [0054]     Moreover, four same units can be used as the level detection units  21 ,  31 ,  41  and the operation unit  60  by the switching operation of the master/slave switch; thus, the laser level detection system can be constructed with a lower price.  
         [0000]     Second Embodiment  
         [0055]      FIG. 7  shows a second embodiment. In the second embodiment, a first level detection device  110  is provided in a pole  102  disposed in a blade (work device)  101  of a bulldozer (construction vehicle)  100 , and a second level detection device  120  is provided in a pole  104  disposed in a ripper (work device)  103  of the bulldozer  100 . The first level detection device  110  comprises the level detection units  21 ,  31 ,  41  similar to the first embodiment, and the second level detection device  120  comprises level detection units  21 ′,  31 ′,  41 ′. The level detection units  21 ,  31 ,  31  are disposed along the longitudinal direction of the pole  102 , and the level detection units  21 ′,  31 ′,  41 ′ are disposed along the longitudinal direction of the pole  104 . An operation unit  160  having the same structure as the operation unit  60  is disposed in an operating room  100 A of the bulldozer  100 . The operation button (not shown) of the operation unit  160  is operated to select one of the first and second level detection devices  110 ,  120  according to the operation of the blade  101  or the ripper  103 . One of the level detection units  21 ,  31 ,  41  of the selected first level detection device  110 , for example, or one of the level detection units  21 ′,  31 ′,  41 ′ of the second level detection device  120  is selected.  
         [0056]     The difference between the light-receiving position of light-receiving section of the selected laser level detection unit and the reference position of light-receiving section is displayed on the operation unit  160 . Thereby, sand and rock can be scraped by the ripper  103  at predetermined height and also the ground can be bulldozed by the blade  101  at predetermined height.  
         [0057]     Conventionally, the ground leveling was risky because it was necessary to confirm the front of traveling direction while confirming the height of ripper  103  disposed backward. However, according to the second embodiment, since the height of ripper  103  is displayed on the operation unit  160 , the height of ripper  103  can be confirmed while observing ahead. Therefore, the ground leveling can be safely performed.  
         [0058]     In the present embodiment, the first and second level detection devices  110 ,  120  comprise three level detection units  21 ,  31 ,  41 ,  21 ′,  31 ′,  41 ′, respectively. However, the first and second level detection devices may comprise one level detection unit, respectively.  
         [0000]     Third Embodiment  
         [0059]      FIG. 8  shows a structure of laser level detection system according to a third embodiment. In the third embodiment, an operation unit  301  similar to the operation unit  60  of the first embodiment is disposed in an observation house  300 . The operation unit  301  displays on a display section (not shown) the difference between the light-receiving position of light-receiving section of the level detection unit of the each of the level detection devices  20 ,  110 ,  120  and the reference position of light-receiving section by the wireless sending and receiving between the operation unit  60  of the hydraulic shovel car  12  (reference to  FIG. 1 ) and the operation unit  160  of bulldozer  100  (reference to  FIG. 7 ). Therefore, the progress in each of the operation sites can be monitored in a remote place.  
         [0060]     If the master is set by a master/slave switch (not show), and a display mode is set by a mode switch (not show), the operation unit  301  displays the difference onto a display section (not shown) of the operation unit  301 .  
         [0061]     In the above embodiments, each of the level detection devices  20 ,  110 ,  120  comprises three level detection units. As long as a plurality of units is used for each of the level detection devices, the number of level detection units is not limited three.  
         [0062]     Although the present invention has been described in terms of exemplary embodiments, it is not limited thereto. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims.  
         [0063]     The present application is based on and claims priority from Japanese Patent Application Serial No. 2005-288396, filed Sep. 30, 2005, the disclosure of which is hereby incorporated by reference herein in its entirety.