Patent Publication Number: US-2020281424-A1

Title: Backpack dust collector

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2019-039485 filed in Japan on Mar. 5, 2019. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a backpack dust collector. 
     2. Description of the Related Art 
     A backpack dust collector includes a fan and a motor configured to generate motive power for rotating the fan. By rotating the fan, air is suctioned with dust through a suction port of the backpack dust collector. The air suctioned through the suction port flows through an internal space of the backpack dust collector, and is then discharged through an exhaust port. An example of related art is described in JP-A-2017-018567. 
     The dust suctioned through the suction port is caught and collected by a dust collecting bag accommodated in a dust collecting chamber of the backpack dust collector. Fine dust that cannot be caught by the dust collecting bag is caught and collected by a filter disposed in the dust collecting chamber. When the filter has been clogged, suction force of the dust collector may be reduced. 
     An object of an aspect of the present invention is to suppress reduction of suction force. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the present invention, a backpack dust collector includes a housing and a filter. The housing includes a suction port, a dust collecting chamber connected to the suction port and accommodating a dust collecting bag, a motor chamber connected to the dust collecting chamber and accommodating a fan and a motor, and an exhaust port through which air from the motor chamber is discharged. The filter is disposed on a side of the dust collecting chamber so as to face the dust collecting chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a backpack dust collector according to a first embodiment; 
         FIG. 2  is a side view of the backpack dust collector according to the first embodiment; 
         FIG. 3  is a sectional view of the backpack dust collector according to the first embodiment; 
         FIG. 4  is a front view of the backpack dust collector according to the first embodiment; 
         FIG. 5  is a perspective view of the backpack dust collector according to the first embodiment; 
         FIG. 6  is a sectional view of the vicinity of a drive unit according to the first embodiment; 
         FIG. 7  is a diagram illustrating the vicinity of an exhaust port according to the first embodiment; 
         FIG. 8  is a diagram illustrating the exhaust port according to the first embodiment when viewed from below; 
         FIG. 9  is a sectional view of a dust collecting bag according to the first embodiment; 
         FIG. 10  is a diagram for describing motion of a vibration device according to the first embodiment; 
         FIG. 11  is a diagram for describing motion of an operating member according to the first embodiment; 
         FIG. 12  is a top view schematically illustrating motion when batteries according to the first embodiment are mounted on battery mounting portions; 
         FIG. 13  is a diagram schematically illustrating a state in which a battery according to the first embodiment is mounted on a battery mounting portion; 
         FIG. 14  is a sectional view of a backpack dust collector according to a second embodiment; 
         FIG. 15  is a diagram schematically illustrating a vibration device according to a third embodiment; 
         FIG. 16  is a diagram schematically illustrating a vibration device according to a fourth embodiment; and 
         FIG. 17  is a block diagram illustrating a vibration device according to a fifth embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will now be described with reference to the drawings. However, the present invention is not limited to these embodiments. Components according to the respective embodiments may be combined appropriately. Some components may be omitted. 
     In the following description, the terms “left”, “right”, “front”, “rear”, “up”, and “down” are used to describe positional relations of the respective components. These terms indicate relative positions or directions with respect to an operator WM. 
     First Embodiment 
       FIG. 1  is a side view of a backpack dust collector  1  according to the present embodiment. As illustrated in  FIG. 1 , the backpack dust collector  1  is used while being carried on an operator WM&#39;s back. The backpack dust collector  1  includes a housing  2 , a hose  4  connected to a suction port  3  of the housing  2 , a pipe  5  connected to the hose  4 , a nozzle  6  connected to the pipe  5 , one or more battery mounting portions  8  on each of which a general-purpose battery  7  is mounted, and an operation unit  9 . 
     The general-purpose battery  7  can be used as a power supply for electrical machinery and apparatus of various types. The general-purpose battery  7  can be used as a power supply for a power tool. The general-purpose battery  7  can be used also as a power supply for electric machinery and apparatus other than the power tool. The general-purpose battery  7  can be used also as a power supply for a dust collector other than the backpack dust collector  1  according to the present embodiment. In the following description, the general-purpose battery  7  is called “battery  7 ” as appropriate. 
     The housing  2  is carried on the operator WM&#39;s back. The housing  2  is attached to the operator WM&#39;s back with shoulder belts  10 A and a waist belt  10 B. The shoulder belts  10 A are attached to the operator WM&#39;s shoulders. The waist belt  10 B is attached to the operator WM&#39;s waist. 
     The housing  2  has an internal space. The housing  2  has a front surface  2 A facing forward, a rear surface  2 B facing rearward, an upper surface  2 C facing upward, a lower surface  2 D facing downward, a left side surface  2 E facing leftward, and a right side surface  2 F facing rightward. In a state in which the housing  2  is carried on the operator WM&#39;s back, the front surface  2 A of the housing  2  faces the operator WM&#39;s back. 
     The suction port  3  is disposed in an upper portion of the housing  2 . The hose  4  is flexible. One end portion of the hose  4  is connected to the suction port  3 . The other end portion of the hose  4  is connected to one end portion of the pipe  5 . The nozzle  6  is connected to the other end portion of the pipe  5 . The nozzle  6  has a suction opening. 
     The housing  2  has one or more battery openings  11  through which the corresponding batteries  7  can pass and one or more battery receiving portions  12  connected to the corresponding battery openings  11 . Each battery  7  is received by the corresponding battery receiving portion  12 . Each battery opening  11  is disposed in a lower portion of the housing  2 . Each battery mounting portion  8  is arranged in the corresponding battery receiving portion  12 . 
     The operation unit  9  is operated by the operator WM. The operation unit  9  includes a switch for starting up the backpack dust collector  1 . The operation unit  9  is attachable to the waist belt  10 B. 
       FIG. 2  is a side view of the backpack dust collector  1  according to the present embodiment.  FIG. 3  is a sectional view of the backpack dust collector  1  according to the present embodiment taken along line A-A in  FIG. 2 .  FIG. 4  is a front view of the backpack dust collector  1  according to the present embodiment.  FIG. 5  is a perspective view of the backpack dust collector  1  according to the present embodiment. 
     The housing  2  includes a base housing  20  having an internal space and a plate  23  connected to the base housing  20 . The base housing  20  includes a front housing  21  and a rear housing  22 . The front housing  21  and the rear housing  22  are connected to each other. The plate  23  is connected to the front housing  21 . The plate  23  is fixed to the front housing  21  with a plurality of threaded bosses  25 . In  FIG. 4  and  FIG. 5 , the plate  23  is indicated by an imaginary line. 
     The front housing  21  includes part of the upper surface  2 C, part of the lower surface  2 D, part of the left side surface  2 E, and part of the right side surface  2 F. The rear housing  22  includes the rear surface  2 B, part of the upper surface  2 C, part of the lower surface  2 D, part of the left side surface  2 E, and part of the right side surface  2 F. A rear end portion of the front housing  21  and a front end portion of the rear housing  22  are connected to each other, whereby the internal space of the base housing  20  is defined. 
     The front housing  21  has a recessed portion  24  formed therein. The recessed portion  24  is recessed rearward in a lower portion of the front housing  21 . The plate  23  is disposed so as to cover the opening of the recessed portion  24 . The plate  23  includes the front surface  2 A. In a state in which the housing  2  is carried on the operator WM&#39;s back, the plate  23  faces the operator WM&#39;s back. 
     The housing  2  includes the suction port  3 , a dust collecting chamber  13  connected to the suction port  3 , a motor chamber  15  connected to the dust collecting chamber  13  with a flow path  14  interposed therebetween, and an exhaust port  17  connected to the motor chamber  15  with a flow path  16  interposed therebetween. 
     The dust collecting chamber  13 , the flow path  14 , the motor chamber  15 , and part of flow path  16  are defined as the internal space of the base housing  20 . Part of the flow path  16  is defined between the recessed portion  24  of the front housing  21  and the plate  23 . 
     The dust collecting chamber  13  is disposed in an upper portion of the internal space of the base housing  20 . The dust collecting chamber  13  is defined by a partition wall  13 W arranged in at least part of the perimeter of the dust collecting chamber  13 . The dust collecting chamber  13  accommodates a dust collecting bag  18 . The dust collecting bag  18  is connected to the suction port  3 . The dust collecting bag  18  is a paper bag, for example. The dust collecting bag  18  is configured to catch and collect dust. 
     The motor chamber  15  is disposed below the dust collecting chamber  13  in the internal space of the base housing  20 . The motor chamber  15  is defined by a partition wall  15 W arranged in at least part of the perimeter of the motor chamber  15 . The motor chamber  15  accommodates a drive unit  30  including a fan  31  and a motor  32 . 
     The flow path  14  is disposed in a right portion of the internal space of the base housing  20 . The flow path  14  is defined by a partition wall  14 W arranged in at least part of the perimeter of the flow path  14 . The flow path  14  extends in an up-and-down direction. The flow path  14  connects a right portion of the dust collecting chamber  13  and a right portion of the motor chamber  15 . 
     In a boundary between the dust collecting chamber  13  and the flow path  14 , a filter  19  is disposed. The filter  19  is a high-efficiency particulate air filter (HEPA), for example. The filter  19  is disposed on a side of the dust collecting chamber  13 . In the present embodiment, the filter  19  is disposed on the right side of the dust collecting chamber  13 . The filter  19  extends in the up-and-down direction. The filter  19  is disposed so as to face the dust collecting chamber  13 . 
     The flow path  16  connects the motor chamber  15  and the exhaust port  17 . Air from the motor chamber  15  is discharged to a space outside the housing  2  through the exhaust port  17 . 
       FIG. 6  is a sectional view of the vicinity of the drive unit  30  according to the present embodiment. As illustrated in  FIG. 6 , the drive unit  30  includes the fan  31 , the motor  32  configured to generate motive power for rotating the fan  31 , a fan cover  33  accommodating the fan  31 , a motor case  34  supporting the motor  32 , a damper  36  disposed around the motor case  34 , a motor support  37  supporting the motor case  34 , and a support ring  38  disposed around the fan cover  33 . The drive unit  30  is accommodated in the motor chamber  15 . 
     The fan  31  is rotatable about a rotation axis AX. The fan  31  is disposed in the motor chamber  15  below the dust collecting chamber  13  such that the rotation axis AX is orthogonal to the up-and-down direction. The rotation axis AX of the fan  31  extends in a right-and-left direction. An output shaft  32 S of the motor  32  is coupled to the fan  31 . The rotation axis of the motor  32  corresponds to the rotation axis AX of the fan  31 . By driving the motor  32 , the fan  31  is rotated about the rotation axis AX. 
     The motor case  34  is disposed around the motor  32 . The damper  36  absorbs noise generated by the motor  32 . In other words, the damper  36  has a noise-absorbing function. Examples of the damper  36  include a sponge. 
     The motor support  37  and the support ring  38  each are an elastic member like rubber. The motor case  34  is fixed to the housing  2  with the motor support  37  and the support ring  38  interposed therebetween. 
     The backpack dust collector  1  includes a control board  35  disposed in the motor chamber  15 . In the present embodiment, the control board  35  serves as a partition wall that defines the motor chamber  15 . The control board  35  is disposed on the left side of the motor  32 . The control board  35  is disposed downstream of the motor  32  such that a surface of the control board  35  is orthogonal to the rotation axis AX of the fan  31 . 
       FIG. 7  is a diagram illustrating the vicinity of the exhaust port  17  according to the present embodiment.  FIG. 8  is a diagram illustrating the exhaust port  17  according to the present embodiment when viewed from below. In  FIG. 7 , the plate  23  is indicated by an imaginary line. 
     The backpack dust collector  1  includes a slit portion  40  disposed in the flow path  16  between the motor chamber  15  and the exhaust port  17  and having slit-shaped vents  41  through which air from the motor chamber  15  passes. 
     The slit portion  40  is provided to at least part of the housing  2 . In the present embodiment, the slit portion  40  is provided to the front housing  21 . That is, the vents  41  are disposed in part of the front housing  21 . 
     The vent  41  is narrow and long in the right-and-left direction. The longitudinal direction of the vent  41  corresponds to the right-and-left direction, and the crosswise direction of the vent  41  corresponds to the up-and-down direction. The vents  41  are arranged in the up-and-down direction. Between the vents  41  adjacent to each other, a rib  43  is provided. 
     The slit portion  40  is disposed in the flow path  16  between the motor chamber  15  and the exhaust port  17 . The ribs  43  of the slit portion  40  divide the flow path  16  into a flow path  16 A near the motor chamber  15  and a flow path  16 B near the exhaust port  17 . The flow path  16 A between the motor chamber  15  and the slit portion  40  is defined in the internal space of the base housing  20 . As illustrated in  FIG. 3  and  FIG. 6 , the flow path  16 A is defined by a partition wall  16 W arranged in at least part of the perimeter of the flow path  16 A. The flow path  16 B between the slit portion  40  and the exhaust port  17  is defined between the recessed portion  24  of the front housing  21  and the plate  23 . 
     The dimension of each vent  41  in the crosswise direction is small. The dimension of the vent  41  in the crosswise direction is so small that foreign matters in a space outside the housing  2  are prevented from entering the internal space (flow path  16 A) of the housing  2 . 
     The flow path  16 B extends in the up-and-down direction. The flow path  16 B is defined between an inner surface  24 A of the recessed portion  24  of the front housing  21  and a rear surface  23 B of the plate  23 . The exhaust port  17  is defined in a lower end portion of the flow path  16 B. In other words, the exhaust port  17  is defined by a lower end portion of the inner surface  24 A of the recessed portion  24  and a lower end portion of the rear surface  23 B of the plate  23 . 
     In a state in which the housing  2  is carried on the operator WM&#39;s back, the vents  41  face laterally. In the present embodiment, the vents  41  face rightward. In the state in which the housing  2  is carried on the operator WM&#39;s back, the exhaust port  17  faces downward. 
     The backpack dust collector  1  includes a noise-absorbing member  42  disposed in at least part of the flow path  16 B between the vents  41  and the exhaust port  17 . 
     As illustrated in  FIG. 7  and  FIG. 8 , the noise-absorbing member  42  is disposed so as to face the vents  41 . The noise-absorbing member  42  faces each of the vents  41 . At least part of the noise-absorbing member  42  is fixed to the inner surface  24 A of the recessed portion  24 . At least part of the noise-absorbing member  42  is fixed to the rear surface  23 B of the plate  23 . 
     The noise-absorbing member  42  includes a porous member. The noise-absorbing member  42  absorbs noise transmitted through air to suppress generation of noise. Examples of noise generated by the backpack dust collector  1  include wind noise generated when air passes through the vents  41  and NZ noise generated by rotation of the fan  31 . 
     The noise-absorbing member  42  is an open-cell porous member. The noise-absorbing member  42  has numerous minute cells. The open cell means that the cells are connected to one another. As the open-cell porous member, at least one of soft urethane sponge, glass wool, rock wool, and felt is exemplified. 
     The open cell has a noise-absorbing function. Noise impinges on the cells at a surface of the noise-absorbing member  42 . The noise impinging on the cells at the surface of the noise-absorbing member  42  propagates to adjacent cells. The noise strikes the inner surfaces of the cells. The cells are connected to one another. The noise propagates to other cells while reflecting off the inner surfaces of the cells. The energy of the noise is attenuated by striking the inner surfaces of the cells many times. Thus, the noise is reduced. 
     As illustrated in  FIG. 7 , the distance D 1  between each vent  41  and the noise-absorbing member  42  is shorter than the distance D 2  between the vent  41  and the exhaust port  17 . The distance D 2  is at least two times longer than the distance D 1 . The distance D 1  is a distance between the center of the vent  41  in the longitudinal direction of the vent  41  and the noise-absorbing member  42 . 
     The fan  31  rotates about the rotation axis AX, thereby generating suction force at the suction port  3 . Air that has been suctioned with dust through the suction opening of the nozzle  6  by generating the suction force at the suction port  3  passes through the pipe  5  and the hose  4 . 
     As indicated by arrows in  FIG. 3 ,  FIG. 6 , and  FIG. 7 , the air that has passed through the pipe  5  and the hose  4  is introduced into the dust collecting chamber  13  through the suction port  3 . To the suction port  3 , the dust collecting bag  18  is connected. Dust contained in the air is caught and collected by the dust collecting bag  18 . The air passes through the dust collecting bag  18 . The air that has passed through the dust collecting bag  18  passes through the filter  19 . The filter  19  catches and collects fine dust that cannot be caught by the dust collecting bag  18 . The air that has passed through the filter  19  passes through the flow path  14 , and then flows into the motor chamber  15 . The air that has flowed into the motor chamber  15  passes through the fan  31  and the motor  32 , comes into contact with the control board  35 , and then flows into the flow path  16 A. The air that has flowed through the flow path  16 A passes through the vents  41  and flows into the flow path  16 B. The air that has flowed through the flow path  16 B is discharged through the exhaust port  17 . 
     The slit-shaped vents  41  prevent foreign matters from entering the flow path  16 A. Air flowing through the vents  41  may generate noise like wind noise. In the present embodiment, the noise-absorbing member  42  is disposed downstream of the vents  41 . The noise-absorbing member  42  suppresses generation of such noise. 
       FIG. 9  is a sectional view of the dust collecting bag  18  according to the present embodiment. As illustrated in  FIG. 9 , when dust has been accumulated in the dust collecting bag  18 , load due to the weight of the dust is applied to the bottom surface of the dust collecting chamber  13  from the dust collecting bag  18 . In the present embodiment, the filter  19  is disposed on a side of the dust collecting chamber  13  so as to face the dust collecting chamber  13  in a state in which the housing  2  is carried on the operator WM&#39;s back. In the present embodiment, the filter  19  is disposed on the right side of the dust collecting chamber  13 . This prevents the filter  19  from being clogged by the dust collecting bag  18  even when dust has been accumulated in the dust collecting bag  18 . Because the filter  19  is prevented from being clogged, reduction of the suction force of the backpack dust collector  1  is suppressed. 
     The backpack dust collector  1  includes a vibration device  50  configured to vibrate the dust collecting bag  18 . As illustrated in  FIG. 9 , at least part of dust may stick to an upper portion of the inner surface of the dust collecting bag  18 . When dust has stuck up to the upper portion of the inner surface of the dust collecting bag  18 , the flow rate of air passing through the dust collecting bag  18  decreases, whereby the suction force of the backpack dust collector  1  may be reduced. When the vibration device  50  vibrates the dust collecting bag  18 , the dust sticking to the upper portion of the inner surface of the dust collecting bag  18  is shaken off, and piles up in a lower portion of the dust collecting bag  18 . Thus, reduction of the suction force of the backpack dust collector  1  is suppressed. 
     In the present embodiment, the vibration device  50  includes a support member  51  supported by elastic members  52  and having a support surface  51 S that can be brought into contact with the dust collecting bag  18 . 
     The support member  51  is a plate-like member. As illustrated in  FIG. 9 , the support member  51  is disposed below the dust collecting bag  18  in the dust collecting chamber  13 . The support surface  51 S includes an upper surface of the support member  51  that can be brought into contact with a lower portion of the dust collecting bag  18 . 
     The elastic members  52  are coil springs, for example. The elastic members  52  support a lower surface of the support member  51 . In the present embodiment, the elastic members  52  are supported by the partition wall  15 W and the partition wall  16 W that are disposed below the support member  51 . The support member  51  is supported by the partition wall  15 W and the partition wall  16 W with the elastic members  52  interposed therebetween. The elastic members  52  support the support member  51  in a swingable manner. 
     The backpack dust collector  1  includes an operating member  53  for moving the support member  51 . The operating member  53  is operated by the operator WM. An upper end portion of the operating member  53  is arranged so as to face a lower surface of the support member  51 . A lower end portion of the operating member  53  is arranged outside the housing  2 . An intermediate portion of the operating member  53  is coupled to at least part of the housing  2  by a hinge  54 . 
       FIG. 10  is a diagram for describing motion of the vibration device  50  according to the present embodiment. When the operator WM moves or walks while carrying the housing  2  on his/her back, the housing  2  moves accordingly. When the housing  2  moves, the support member  51  supported by the elastic members  52  vibrates with an amplitude greater than the amplitude of the housing  2 . When the housing  2  moves, vibrations of the housing  2  are transmitted to the support member  51  in an amplified manner due to the effect of the elastic members  52 . When the support member  51  vibrates greatly, the dust collecting bag  18  supported by the support member  51  accordingly vibrates greatly. When the dust collecting bag  18  vibrates greatly, dust sticking to an upper portion of the inner surface of the dust collecting bag  18  is shaken off, and piles up in a lower portion of the dust collecting bag  18  as illustrated in  FIG. 10 . Thus, reduction of the suction force of the backpack dust collector  1  is suppressed. 
       FIG. 11  is a diagram for describing motion of the operating member  53  according to the present embodiment. As illustrated in  FIG. 11 , the operator WM can operate the operating member  53  such that the operating member  53  rotates about the rotation axis of the hinge  54 . When the operating member  53  is operated, the upper end portion of the operating member  53  moves up and down while being in contact with the support member  51 . Thus, the support member  51  greatly vibrates up and down. When the support member  51  greatly moves up and down, the dust collecting bag  18  supported by the support member  51  accordingly moves greatly. When the dust collecting bag  18  vibrates greatly, dust sticking to an upper portion of the inner surface of the dust collecting bag  18  is shaken off, and piles up in a lower portion of the dust collecting bag  18  as illustrated in  FIG. 11 . Thus, reduction of the suction force of the backpack dust collector  1  is suppressed. 
     As illustrated in  FIG. 2 ,  FIG. 3 ,  FIG. 5 , and  FIG. 6 , the battery openings  11  are formed each on the left side surface  2 E and the right side surface  2 F of the housing  2 . The battery openings  11  and the battery receiving portions  12  are formed in lower portions of the housing  2 . 
     Each battery mounting portion  8  is arranged on an upper surface of the corresponding battery receiving portion  12 . The battery mounting portion  8  has guide rails  81  configured to guide the corresponding battery  7  and a connection terminal  82  configured to be connected to a battery terminal  72  of the battery  7 . The guide rails  81  extend in the right-and-left direction. The guide rails  81  in a pair are arranged in the front-and-rear direction. The guide rails  81  in a pair are arranged in parallel. The connection terminal  82  is arranged between the pair of guide rails  81 . 
     The battery  7  is a general-purpose battery. The battery  7  may be a battery for a power tool. In the present embodiment, the battery  7  can be used as a direct-current power supply for a power tool. The battery  7  includes a plurality of lithium ion battery cells. The battery  7  can be charged by a battery charger. The battery  7  is portable. The battery  7  supplies power to at least the motor  32 . 
     The battery  7  has a pair of slide rails  71  to be guided by the guide rails  81 , the battery terminal  72  to be connected to the connection terminal  82  of the battery mounting portion  8 , and a release button  73 . 
     The slide rails  71  are guided by the guide rails  81  of the battery mounting portion  8 . The slide rails  71  in a pair are arranged in parallel. The battery terminal  72  is arranged between the pair of slide rails  71 . In a state in which the battery  7  is mounted on the battery mounting portion  8 , the battery terminal  72  is connected to the connection terminal  82 . 
     The release button  73  is operated to release the battery  7  fixed to the battery mounting portion  8 . The release button  73  is provided on one end surface  7 A of the battery  7 . The battery  7  is mounted on the battery mounting portion  8  such that the release button  73  is directed outward in the right-and-left direction with respect to the center of the housing  2 . In the state in which the battery  7  is mounted on the battery mounting portion  8 , the release button  73  faces the battery opening  11 . 
     In the present embodiment, the battery mounting portion  8  is inclined downward in the battery receiving portion  12  as farther from the battery opening  11 . In other words, the battery mounting portion  8  is inclined downward toward a deeper position in the battery receiving portion  12 . The guide rails  81  are inclined downward in the battery receiving portion  12  as farther from the battery opening  11 . 
     The front housing  21  and the rear housing  22  have respective bottom plates  26  that define bottom surfaces  2 P of the battery receiving portion  12 . Each of the bottom surfaces  2 P faces part of the corresponding lower surface of the battery  7  mounted on the battery mounting portion  8 . The bottom surfaces  2 P are inclined downward in the battery receiving portion  12  as farther from the battery opening  11 . The bottom plate  26  of the front housing  21  is fixed to at least part of the front housing  21  with a rib interposed therebetween. The bottom plate  26  of the rear housing  22  is fixed to at least part of the rear housing  22  with a rib interposed therebetween. In a lower portion of the battery receiving portion  12 , an opening  12 K is disposed. The opening  12 K is disposed between the bottom plate  26  of the front housing  21  and the bottom plate  26  of the rear housing  22 . 
     The front housing  21  and the rear housing  22  have respective inner side plates  27  that define inner side surfaces  2 Q connected to the battery opening  11 . Each inner side surfaces  2 Q faces part of the corresponding side surface of the battery  7  passing through the battery opening  11 . The inner side surfaces  2 Q of the front housing  21  are inclined rearward in the battery receiving portion  12  as farther from the battery opening  11 . The inner side surfaces  2 Q of the rear housing  22  are inclined forward in the battery receiving portion  12  as farther from the battery opening  11 . In other words, the width of a passage in the front-and-rear direction through which the battery  7  passes in the battery receiving portion  12  is smaller in the battery receiving portion  12  as farther from the battery opening  11 . 
       FIG. 12  is a top view schematically illustrating motion when the batteries  7  according to the present embodiment are mounted on the battery mounting portions  8 . When mounting the batteries  7  on the battery mounting portions  8 , the operator WM inserts the batteries  7  into the battery receiving portions  12  disposed in the left side surface  2 E and the right side surface  2 F through the respective battery openings  11 , thereby being able to mount the batteries  7  on the battery mounting portions  8 . 
     When mounting a battery  7  on the left battery mounting portion  8 , the operator WM inserts the battery  7  into the battery opening  11  disposed at the left side surface  2 E. The operator WM slides the battery  7  rightward while causing the guide rails  81  of the battery mounting portion  8  to guide the slide rails  71  of the battery  7 . When the battery  7  has been slid rightward, the battery  7  is fixed to the battery mounting portion  8 , and the battery terminal  72  of the battery  7  is connected to the connection terminal  82  of the battery mounting portion  8 . Thus, the battery  7  is mounted on the battery mounting portion  8 . 
     When mounting a battery  7  on the right battery mounting portion  8 , the operator WM inserts the battery  7  into the battery opening  11  formed at the right side surface  2 F, and then slides the battery leftward, thereby being able to mount the battery  7  on the battery mounting portion  8 . 
     As illustrated in  FIG. 2  and  FIG. 12 , in the present embodiment, the dimension W 11  of each battery opening  11  in the front-and-rear direction is larger than the dimension W 12  of the corresponding battery receiving portion  12  in the front-and-rear direction where the corresponding guide rails  81  are arranged. The dimension W 11  corresponds to the distance between end portions of the pair of inner side surfaces  2 Q that are closest to the battery opening  11 . The dimension W 12  corresponds to the distance between end portions of the pair of inner side surfaces  2 Q that are closest to the guide rails  81 . Because the dimension W 11  of the battery opening  11  is large, the operator WM can insert the corresponding battery  7  smoothly into the battery opening  11 . The operator WM can insert the battery  7  into the battery opening  11  while holding, for example, side surfaces of the battery  7 . Because the dimension W 12  of the battery receiving portion  12  is small, the battery  7  can be moved in the battery receiving portion  12  while being guided by the inner side surfaces of the battery receiving portion  12  that are located deeper than the corresponding inner side plates  27  and also by the guide rails  81  in the battery receiving portion  12 . 
     Furthermore, because the corresponding bottom plate  26  is provided, the battery  7  can be prevented from falling from the battery receiving portion  12  when the battery  7  is mounted on the battery mounting portion  8  or when the battery  7  is pulled out of the battery mounting portion  8 . 
     As illustrated in  FIG. 3  and  FIG. 6 , the backpack dust collector  1  includes moving mechanisms  74  each disposed in the corresponding battery receiving portion  12  and configured to generate force for moving the corresponding battery  7  toward the corresponding battery opening  11 . Each moving mechanism  74  is disposed at a position where it can be in contact with the corresponding battery  7 . 
     The moving mechanism  74  includes an elastic member  74 E. Examples of the elastic member  74 E include a leaf spring. The elastic member  74 E may include a coil spring. 
     The elastic member  74 E is disposed so as to face the other end surface  7 B of the battery  7  in a state in which the battery  7  is mounted on the battery mounting portion  8 . The elastic member  74 E is disposed on the opposed surface  12 A of the battery receiving portion  12 . In the state in which the battery  7  is mounted on the battery mounting portion  8 , the other end surface  7 B of the battery  7  faces the opposed surface  12 A. In the state in which the battery  7  is mounted on the battery mounting portion  8 , the other end surface  7 B of the battery  7  is in contact with the elastic member  74 E. 
       FIG. 13  is a diagram schematically illustrating a state in which a battery  7  according to the present embodiment is mounted on a battery mounting portion  8 . The guide rails  81  of the battery mounting portion  8  are inclined downward in the corresponding battery receiving portion  12  as farther from the corresponding battery opening  11 . In the state in which the battery  7  is mounted on the battery mounting portion  8 , the other end surface  7 B of the battery  7  is in contact with the corresponding elastic member  74 E. In the state in which the battery  7  is mounted on the battery mounting portion  8 , the elastic member  74 E is elastically deformed by the battery  7 . The elastic member  74 E thus elastically deformed generates elastic force for moving the battery  7  toward the battery opening  11 . 
     When removing the battery  7  from the battery mounting portion  8 , the operator WM operates the corresponding release button  73 . When the release button  73  has been operated, the battery  7  fixed to the battery mounting portion  8  is released. When the battery  7  fixed to the battery mounting portion  8  has been released, the battery  7  is moved toward the battery opening  11  by the elastic force generated by the elastic member  74 E. By the elastic force generated by the elastic member  74 E, at least part of the battery  7  including the one end surface  7 A is ejected outside the battery receiving portion  12  through the battery opening  11 . This allows the operator WM to hold the battery  7  smoothly. While holding the battery  7  pulled out of the battery mounting portion  8 , the operator WM can remove the battery from the battery receiving portion  12 . 
     As described in the foregoing, according to the present embodiment, the filter  19  is disposed on a side of the dust collecting chamber  13  so as to face the dust collecting chamber  13 . This prevents the filter  19  from being clogged by the dust collecting bag  18 . Thus, reduction of the suction force of the backpack dust collector  1  is suppressed. For example, even when dust is accumulated in the dust collecting bag  18 , the filter  19  is prevented from being clogged by the dust collecting bag  18 . 
     The motor chamber  15  is disposed below the dust collecting chamber  13 . The fan  31  is disposed such that the rotation axis AX of the fan  31  is orthogonal to the up-and-down direction. Thus, air that has discharged from the dust collecting chamber  13  and has flowed through the filter  19  and the flow path  14  can flow through the motor chamber  15  in a direction orthogonal to the up-and-down direction. 
     The control board  35  is disposed downstream of the motor  32  such that the surface of the control board  35  is orthogonal to the rotation axis AX. This allows air from the fan  31  to blow against the control board  35  sufficiently. Thus, the control board  35  is effectively cooled. 
     The suction port  3  is disposed in an upper portion of the housing  2 . This enables dust suctioned from the suction port  3  to move to a lower portion of the dust collecting bag  18  by the action of gravity. Dust is prevented from sticking to an upper portion of the inner surface of the dust collecting bag  18 . 
     The vibration device  50  configured to vibrate the dust collecting bag  10  is provided. This enables dust to be shaken off even if the dust has stuck to the inner surface of the dust collecting bag  18 . Because the dust is shaken off from the inner surface of the dust collecting bag  18 , reduction of the suction force of the backpack dust collector  1  is suppressed. 
     The vibration device  50  includes the support member  51  supported by the elastic members  52  and having the support surface  51 S capable of being brought into contact with the dust collecting bag  18 . Thus, the operator WM can vibrate the dust collecting bag  18  by moving or walking while carrying the backpack dust collector  1  on his/her back. 
     The support member  51  is disposed below the dust collecting bag  18  in the dust collecting chamber  13 . This allows the dust collecting bag  18  to be shaken from below, and thus dust sticking to the inner surface of the dust collecting bag  18  is effectively shaken off. 
     The operating member  53  for moving the support member  51  is provided. This enables the operator WM to vibrate the dust collecting bag  18  at any timing. 
     Second Embodiment 
     In the following description, components that are the same as or equivalent to those in the above-described embodiment are designated by the same signs, and description thereof is simplified or omitted. 
       FIG. 14  is a sectional view of a backpack dust collector  1 B according to the present embodiment. In the above-described embodiment, the suction port  3  is disposed on the upper surface  2 C of the housing  2 . As illustrated in  FIG. 14 , the suction port  3  may be disposed on the left side surface  2 E of the housing  2 . Alternatively, the suction port  3  may be disposed on the right side surface  2 F of the housing  2 . 
     Third Embodiment 
       FIG. 15  is a diagram schematically illustrating a vibration device  50 C according to the present embodiment. As illustrated in  FIG. 15 , the vibration device  50 C includes a vibrating element  59  connected to an upper portion of the dust collecting bag  18 . The vibrating element  59  is disposed in the dust collecting chamber  13 . The vibrating element  59  can impart vibrations to the upper portion of the dust collecting bag  18 . When the vibrating element  59  is driven, dust sticking to an upper portion of the inner surface of the dust collecting bag  18  is effectively shaken off. 
     Fourth Embodiment 
       FIG. 16  is a diagram schematically illustrating a vibration device  50 D according to the present embodiment. The vibration device  50 D includes a flow path  56 F connecting the dust collecting chamber  13  and a space outside the housing  2  and a valve  56  configured to open and close the flow path  56 F. The flow path  56 F is disposed at a position different from that of the suction port  3 . When the dust collecting bag  18  is vibrated, the motor  32  is driven with the suction port  3  being closed by a lid  55  and with the flow path  56 F being closed by the valve  56 . This causes pressure in the dust collecting chamber  13  to decrease. After the pressure in the dust collecting chamber  13  has decreased, the valve  56  is operated to open the flow path  56 F. When the flow path  56 F has been opened in a state in which the pressure in the dust collecting chamber  13  had decreased, air in a space outside the housing  2  flows into the dust collecting chamber  13  through the flow path  56 F. The air in a space outside housing  2  flows into the dust collecting chamber  13  at high velocity. By the air flowing into the dust collecting chamber  13 , the dust collecting bag  18  is vibrated. In the present embodiment, too, dust sticking to the inner surface of the dust collecting bag  18  is shaken off. 
     Fifth Embodiment 
       FIG. 17  is a block diagram illustrating a vibration device  50 E according to the present embodiment. As illustrated in  FIG. 17 , the vibration device  50 E includes the control board  35 , a rotational speed sensor  57 A configured to detect the number of revolutions of the motor  32 , a suction force sensor  57 B configured to detect suction force at the suction port  3 , and a vibrating element  58  disposed so as to be in contact with the dust collecting bag  18 . 
     The control board  35  causes the vibrating element  58  to be driven based on detection data of the rotational speed sensor  57 A. For example, when it is determined that the motor  32  has stopped being driven and the number of revolutions of the motor  32  has reached a first threshold or smaller, the control board  35  starts up the vibrating element  58 . The first threshold is a predetermined value. When the number of revolutions of the motor  32  has decreased, the vibrating element  58  vibrates the dust collecting bag  18 , thereby effectively shaking off dust sticking to the inner surface of the dust collecting bag  18 . 
     The control board  35  may cause the vibrating element  58  to be driven based on detection data of the suction force sensor  57 B. For example, when it is determined that the motor  32  has stopped being driven and the suction force has reached a second threshold or smaller, the control board  35  starts up the vibrating element  58 . The second threshold is a predetermined value. When the suction force has decreased, the vibrating element  58  vibrates the dust collecting bag  18 , thereby effectively shaking off dust sticking to the inner surface of the dust collecting bag  18 . 
     According to an aspect of the present invention, reduction of the suction force can be suppressed.