JPH0335256Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an indicator for a vacuum cleaner that functions both as a dust collection meter and a safety valve.

[Prior Art] Conventionally, an indicator 50 of a vacuum cleaner that functions as both a dust collection meter and a safety valve is shown in FIGS.
As shown in FIG. 10, a cylinder 51, a piston 52 slidably disposed inside the cylinder 51, and a piston 52 biased in a direction to close the suction hole 54 of the cylinder 51. It is constituted by a spring body 53.

A suction hole 54 communicating with the outside air is provided at one end of the cylinder 51, and an exhaust port 55 communicating with the suction side of an electric blower (not shown) is provided at the other end. A piston 52 is slidably disposed on the holder.

A rib 56 is erected on the outer peripheral surface of the piston 52 along the sliding direction, and is biased by a spring body 53 in a direction to close the suction hole 54 of the cylinder 51.

Therefore, as shown by the arrow It passes through the inside of the spring body 53 and is formed from the discharge port 55 to the suction side of the electric blower.

In addition, the types shown in Figures 11 to 14 are
The outer peripheral surface of the piston 61 is provided with ribs 6 as described above.
6 is erected along the sliding direction,
A piston 61 is provided on the outer peripheral surface of the electric blower on the suction side.
A hole 68 communicating with the inside is transparently provided.

Therefore, the air path of the leakage air from the suction hole 64 is as follows:
As shown by arrow Y, it passes through the gap 67 and enters the inside of the piston 62 from the hole 68, passes through the inside of the spring body 63, and communicates from the discharge port 65 of the cylinder 61 to the suction side of the electric blower.

In this way, in any type, under normal conditions, the suction holes 54, 6 of the cylinders 51, 61
4 is closed by pistons 52 and 62 so that outside air is not drawn into the vacuum cleaner.

Therefore, if the negative pressure on the suction side of the electric blower increases due to filter clogging, etc., the piston 5
2 and 62 slide toward the suction side of the electric blower against the bias of the spring bodies 53 and 63, respectively, so leak air is sucked from the suction holes 54 and 64 of the cylinders 51 and 61, and the dust is collected as a dust collection meter. In addition to displaying the storage status, it also serves as a safety valve.

[Problems to be solved by the invention] Because of this configuration, the former type is capable of absorbing dust floating in the air, especially when fiber dust is sucked into the cylinder 51. teeth,
It is easy to get tangled with the spring body 53. Therefore, when the spring body 53 is compressed by being pressed by the piston 52, the frictional resistance between it and the inner circumferential surface of the cylinder 51 increases due to the fiber dust, making the operating point of the piston 52 unstable, and the accurate It was not possible to display it.

Furthermore, since the air passage is suddenly expanded from the rear end of the piston 52, a vortex is generated at this location. This vortex causes the piston 52 to chatter,
This also caused the operating point of the piston 52 to become unstable.

On the other hand, the latter type was made to solve the problem of operating point failure caused by floating dust, and the leakage air is caused by the gap between the cylinder 61 and the piston 62.
7, from the hole 68 through the inside of the piston 62, and from the inside of the spring body 63 to the discharge port 65 while bending at various places. As shown in FIG. 12, the hole 68 of the piston 62 is open in only two directions, which causes the pressure inside the piston 62 to be uneven.

Therefore, the piston 62 causes chattering, which not only makes the operating point of the piston 62 unstable, but also increases pressure loss. Therefore, since the leakage air volume is also small relative to the opening area, sufficient cooling air for the electric blower cannot be obtained, which has been a cause of failure of the vacuum cleaner main body.

[Means for solving the problem] In this invention, the piston has a cylindrical shape with a bottom, and an air passage is provided in the sliding direction between the inner peripheral surface of the cylinder and the outer peripheral surface of the cylindrical part of the piston. A rectifying rib that forms a gap such as The cylindrical portion of the piston is provided with a cutout hole which is cut out in the circumferential direction except for the part where the rectifying rib is provided and which communicates the inside and outside of the cylindrical portion of the piston. An air passage is formed inside and outside the cylindrical portion of the piston, communicating through a notch hole and guided by a rectifying rib.

[Function] According to this invention, when dust accumulates in the dust collection bag and the negative pressure on the suction side of the electric blower becomes large, the piston slides inside the cylinder, so the suction hole in the cylinder is opened and the leakage air is removed. will flow in.

This leakage air passes through the gap between the cylinder and the piston due to the rectifying rib that forms a gap that serves as an air path in the sliding direction, and flows into the inside of the piston from the notch hole. Therefore, since the leakage air is guided by the rectifying ribs, no vortex is generated.

Since the inside of the piston is provided with a straightening rib extending in the direction of the inner center, an air passage for leakage air guided by the straightening rib is also formed inside the piston, and vortex flow is also prevented inside the piston. This prevents this from occurring, stabilizes the operating point of the piston, and provides a safe and trouble-free vacuum cleaner.

[Embodiment of the invention] An embodiment of the invention will be described in detail based on FIGS. 1 to 6.

In FIGS. 1 to 4, reference numeral 1 denotes a main body of a vacuum cleaner, in which a dust collection chamber 2 is provided in the front part, and an electric blower 3 is provided in the rear part.

Inside the dust collection chamber 2, a dust collection bag 4 is removably attached to a mounting body 5, and a hose outlet (not shown) is removably inserted into the front of the dust collection chamber 2. An auxiliary filter 7 is attached to a lattice-like rib 8 at the rear, and an electric blower 3 is disposed behind the auxiliary filter 7 with a gap 9 interposed therebetween.

Reference numeral 10 denotes an indicator that reads the amount of dust collected in the dust collection bag 4 from the outside and prevents excessive temperature rise due to overload of the electric blower 3 when a large amount of dust is collected in the dust collection bag 4. It is opened to take in cooling air from the atmosphere, and consists of a cylinder 11, a piston 12, a spring body 13, and a main body 1.
and a connecting pipe 15 connecting the cylinder 11 and the cylinder 11.

The cylinder 11 is made of a transparent member and has a cylindrical shape, and one end is provided with a suction hole 14 that communicates with the outside air, and the other end is opened at the gap 9 between the auxiliary filter 7 and the electric blower 3. A discharge port 16 is provided which communicates with the suction side of the electric blower 3 via a connecting pipe 15. The connecting pipe 15 is made of a rubber member, and connects the cylinder 11 and the main body 1.
is connected to.

As shown in FIGS. 5 and 6, the piston 12 is formed into a cylindrical shape with a bottom, and the cylinder 1
A large diameter portion 12a formed to have approximately the same diameter as the inner diameter of 1, and a cylindrical portion 12b having a smaller diameter than this large diameter portion 12a are integrally formed,
The spring body 13 allows the suction hole 14 of the cylinder 11 to
is slidably disposed inside the cylinder 11 in a state where it is biased in the direction of being closed by the cylindrical portion 12b.

On the outer peripheral surface of the cylindrical portion 12b of the piston 12, a rectifying rib 17 is provided upright at a position equiangular to the center of the piston 12 in the sliding direction in order to maintain a gap 20 between the cylinder 11 and the piston 12. At the same time, this rectifying rib 17 also extends toward the center of the inner side of the piston 12 to form an inner rectifying rib 17a.
is formed.

A notch hole 18 is formed by cutting out the outer peripheral surface of the piston 12 in the circumferential direction, excluding the rectifying rib 17, between the large diameter portion 12a and the cylindrical portion 12b of the piston 12. At the same time, the opening edges 19 of the notch holes 18 are each formed to be inclined in the direction of the air passage.

Therefore, the air path of the leak air sucked from the suction hole 14 passes through the gap 20 between the cylinder 11 and the piston 12, which is formed by the rectifying rib 17.
The large diameter portion 12 a communicates with the inside of the spring body 13 via the notch hole 18 and the inside of the piston 12 .

One end of the spring body 13 contacts the end surface of the large diameter portion 12a and urges the cylindrical portion 12b of the piston 12 in a direction to close the suction hole 14 of the cylinder 11.

21 is a handle, 22 is a dust removal device, 23 is a rear wheel, 24 is a caster, and 25 is an exhaust hole.

Next, the operation will be explained.

Under normal conditions, the suction hole 14 of the cylinder 11
is the piston 1 urged by the spring body 13
2 is closed, the leakage air is removed from the main body of the vacuum cleaner 1
It cannot be sucked inside.

Therefore, as dust gradually accumulates in the dust collection bag 4, the negative pressure on the suction side of the electric blower 3, that is, the gap 9 becomes large, and the piston 12
Due to the urging force of , forces are applied in opposite directions to each other. When the differential pressure with atmospheric pressure becomes slightly larger than the biasing force of the spring body 13, the piston 12 slides a short distance within the cylinder 11, and the suction hole 14 of the cylinder 11 is opened, as shown by arrow D. , a small leakage wind flows in.

This leakage air passes through the gap 20 between the cylinder 11 and the piston 12 by the rectifying rib 17 erected on the outer peripheral surface of the piston 12, and passes through the gap 20 between the cylinder 11 and the piston 12.
8 into the piston 12.

At this time, since the opening edges 19 of the notch holes 18 are formed to be inclined in the direction of the leakage airflow path, the leakage airflow flows along these sloped surfaces and is not bent suddenly. No vortices are generated.

The leakage air that has passed through the notch hole 18 enters the inside of the piston 12, but at this time, the piston 12
Since the rectifying ribs 17a are formed inside the piston 12 on its inner circumferential surface, an air passage is also formed inside the piston 12, and the piston 12 is introduced into the inside of the spring body 13 as it is without generating a vortex.

At this time, since the opening edges 19 of the notch holes 18 are formed to be inclined in the air path direction,
The leak air flows more smoothly and the generation of vortices can be prevented.

In this way, the air path of the leak air is formed smoothly so that no vortex is generated, so that the pressure inside the piston 12 becomes uniform.

Next, when the amount of dust collected in the dust collection bag 4 further increases, the degree of vacuum in the gap 9 increases, and the differential pressure across the piston 12 becomes larger than the biasing force of the spring body 13. The suction hole 14 is fully opened and sufficient leakage air is sucked out. This leak air passes through the inside of the spring body 13, passes through the connecting pipe 15, passes through the gap 9, and is exhausted to the outside from the exhaust hole 25 while cooling the electric blower 3.

At this time, the leakage air is exhausted to the gap 9, and
When the degree of vacuum reaches a specified value, the piston 12 is pressed by the spring body 13 and slides in a direction to close the suction hole 14 of the cylinder 11, thereby closing it.

[Effects of the invention] In this invention, the piston has a cylindrical shape with a bottom, and a gap is formed between the inner circumferential surface of the cylinder and the outer circumferential surface of the cylindrical part of the piston, which serves as an air passage in the sliding direction. A rectifying rib is provided upright along the sliding direction on the outer circumferential surface of the cylindrical portion of the piston, and this rectifying rib is also provided on the inner circumferential surface of the cylindrical portion of the piston so as to extend toward the inner center thereof. In addition, a part of the cylindrical part of the piston is cut out in the circumferential direction except for the part where the rectifying rib is erected, and a notched hole is formed to communicate between the inside and outside of the cylindrical part of the piston. Since an air passage is formed inside and outside the cylindrical part through a notch hole and guided by a rectifying rib, the pressure inside the piston remains constant, which prevents the generation of vortices inside the piston. At the same time, the operating point of the piston can be stabilized, and a safe and trouble-free vacuum cleaner can be obtained.

Furthermore, since the leakage air is guided by the rectifying ribs on both the outside and inside of the piston, it can flow smoothly without generating vortices.

Furthermore, since the opening edges of the piston's notch holes that face each other in the sliding direction are sloped, the flow of leakage air from the outside of the piston to the inside becomes smoother, and the operating point of the piston is further stabilized. Since the suction performance can be set high in terms of points,
A vacuum cleaner with good dust absorption performance can be obtained.

Furthermore, since the air path resistance inside the indicator can be reduced, the leakage air volume increases, the cooling effect becomes large, and a safe and trouble-free vacuum cleaner can be obtained.

[Brief explanation of drawings]

Figures 1 to 6 show examples of this invention. Figure 1 is a perspective view, Figure 2 is a sectional view of the vacuum cleaner, Figure 3 is a sectional view of the main part, and Figure 4 is a sectional view of the vacuum cleaner. Figure 3 C-
5 is a perspective view of the piston 12, FIG. 6 is a perspective view taken from the direction of arrow R in FIG. 5, and FIG.
7 to 10 show the first conventional example, FIG. 7 is a cross-sectional view of the main part, FIG. 8 is a cross-sectional view taken along the line A-A in FIG. 7, FIG. 9 is a perspective view of the piston 52, and FIG. 9 is a perspective view taken from the arrow P in FIG. 9, FIGS. 11 to 14 are the second conventional example, FIG. 11 is a sectional view of the main part, FIG. Figure 13 shows the piston 62
FIG. 14 is a perspective view taken from arrow Q in FIG. 13. 1... Main body of the vacuum cleaner, 3... Electric blower,
10...Indicator, 11...Cylinder, 1
2... Piston, 12b... Cylindrical part, 13... Spring body, 14... Suction hole, 16... Discharge port, 17...
... rectifying rib, 18 ... notch hole, 19 ... opening edge of notch hole 18, 20 ... gap.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A cylinder with a suction hole communicating with the atmosphere at one end and an outlet communicating with the suction side of an electric blower at the other end, and a cylinder capable of sliding inside the cylinder. A vacuum cleaner indicator comprising a piston disposed in the cylinder and biased by a spring in a direction to close the suction hole, wherein the piston has a cylindrical shape with a bottom, and the inner circumferential surface of the cylinder and the piston A rectifying rib is provided along the sliding direction on the outer peripheral surface of the cylindrical portion of the piston to form a gap that serves as an air path in the sliding direction between the piston and the outer peripheral surface of the cylindrical portion of the piston. A rib is also provided on the inner circumferential surface of the cylindrical portion of the piston, extending toward the inner center thereof, and a portion of the cylindrical portion of the piston is provided with a rib extending in the circumferential direction except for the portion where the rectifying rib is provided upright. A cutout hole is formed in the cylindrical portion of the piston to communicate between the inside and outside of the cylindrical portion of the piston, and the airflow guided by the rectifying rib is communicated between the inside and outside of the cylindrical portion of the piston through the notch hole. An indicator of a vacuum cleaner characterized by forming a path. (2) Claim 1 of the utility model registration claim provides a vacuum cleaner characterized in that the opening edges of the notched hole of the piston, which are opposite to each other in the sliding direction, are each inclined toward the discharge port side of the cylinder. indicator.