AIR ASPIRATION SYSTEM FOR MEDIA FLOW CONTROL VALVE IN SHOT PEENING

Abstract

This application describes a magnetic valve for controlling the flow of media in wheel-blast style abrasive blasting cabinets. The valve features a novel air aspiration system comprising of aspiration inlets, chamber, and outlets, in a configuration which guarantees passage of air from ambient into the peening system regardless of installation. This system acts as a passive aspiration source to counteract the negative pressures imposed by the wheel-blast blades in the valve's off-state. This arrangement eliminates the need for other means of aspiration to be installed in the peening system by the end user.

Description

TECHNICAL FIELD

This disclosure generally relates to shot peening, and, specifically, providing an air aspiration system for a media flow control valve in shot peening.

BACKGROUND

Shot peening is a surface enhancement process that imparts a compressive residual stress into the surface of a metal component by impacting metallic, ceramic, or glass peening particles at high velocity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a valve for controlling a flow of media.

FIG. 2 a bottom perspective view of the valve of FIG. 1.

FIG. 3 is a section view along line 10 of the valve of FIG. 2.

DETAILED DESCRIPTION

Shot peening is a surface enhancement process that imparts a compressive residual stress into the surface of a metal component by impacting metallic, ceramic, or glass peening media at high velocity. Popular methods for propelling these peening media include air blast systems and wheel blast wheels. In the air blast systems, media are introduced by various methods into the path of high pressure air and accelerated through a nozzle directed at the surface to be peened.

In wheel blast style peening applications, shot peening media is fed from a hopper or media storage bin to the blades of a rotating wheel and propelled toward an impingement target. This media travels through the peening arrangement in very high volumes, in the range of 100-2000 pounds per minute.

To regulate the flow rate of media in wheel blast style peening applications, a flow control device or apparatus is used. The flow control device or apparatus, which in some examples is a valve, but in other examples may be another mechanical component to accomplish the same result while functioning in much the same way, contains a working gap through which media may pass during a peening operation. The apparatus, in some examples a valve, may have a first side or end that is connected to a media feed or media hopper, and may have a second side or end that is connected to a wheel blast style peening unit. In some examples, these devices may be magnetically-closed valves, which may use an arrangement of permanent magnets, electrical coils, and pole pieces constructed from magnetic material to control the advancement of media. When the valve is in its off-state, or a “shut” position, the permanent magnets and magnetic material create a magnetic field which impedes the flow of shot media through the valve.

Thus, when the valve is shut or in its off-state, the valve impedes the shot media fed from the hopper from flowing through the working gap of the valve, the shot media builds up between the hopper and the valve, and thus the working gap of the valve is closed off. Consequently, the movement of the fan in a wheel blast style application creates negative pressure between the feed spout of the wheel blast unit and the control valve. This pressure differential may be sufficient to induce unintended flow of media through the working gap of the flow control device or apparatus, which negatively affects the controlled conditions of the peening process. In prior art, there have been no provisions made for this negative pressure, requiring the user to install additional equipment.

Referring now to the drawings, wherein like numerals refer to the same or similar features in the various views, FIG. 1 is a top perspective view of a housing, in this example a valve 100 that is configured to regulate the flow of media into a wheel blast type peening machine. FIG. 2 is a bottom perspective view of the housing or valve 100. In this example, the valve 100 is structured to reduce or relieve the effect of negative pressures introduced by fans in the wheel blast fans by allowing air to be drawn into the valve 100 passively. This passive air flow is enabled regardless of inconsistent installation, installation with different hoppers, different wheel blast units, and different mechanical mating components, and is protected from debris via a particular arrangement of the air flow passage.

As shown in FIGS. 1 and 2, in some examples the valve 100 includes a working gap 1, pole pieces 2, and an intermediate bar 3. The intermediate bar 3 is fixed at some position within the opening of the working gap 1. The pole pieces 2 are positioned substantially at the perimeter or otherwise within the opening of the working gap 1, such that during operation shot peening media flows from a hopper (not pictured) mounted above the valve, through the working gap 1, and over and between the pole pieces 2 and the intermediate bar 3. However, during the shut or off position of the valve, the pole pieces 2 create a magnetic field together with the intermediate bar 3, which effectively closes or partially closes the working gap 1 by impeding the motion of shot media and causing a buildup of shot media before the working gap 1. In some embodiments, such as those in which the size of the opening of the working gap 1 is smaller, the intermediate bar 3 may be omitted due to the working gap 1 being small enough for the magnetic field from the pole pieces 2 to extend across the working gap 1 and impede the flow of media. Embodiments with the intermediate bar 3 and without the intermediate bar 3 function in the same way, with substantially the same structure, to achieve the same result.

In the example pictured in FIGS. 1 and 2, the valve 100 further includes at least one, but in the example shown a plurality of aspiration inlets 4, aspiration chambers 9, aspiration outlets 5, and media barriers 6.

In the example shown in FIGS. 1 and 2, the plurality of aspiration inlets 4 are located on the valve in a position substantially outside of the area of the working gap 1. Each of the aspiration inlets 4 connect to a first end of an aspiration chamber 9, which in some examples, such as the one shown, are located within the valve 100. The aspiration chambers 9 connect at a second end to an aspiration outlet 5. The aspiration outlet 5 is at a location on the valve substantially within the working gap 1 of the valve 100, such that air exiting the aspiration outlet 5 enters into the main flow of media towards the fan of the wheel blast type peening unit.

In some examples the pole pieces 2 and, or alternatively the intermediate bar 3, may be made from magnetic materials either by machining, casting, or by other mechanical processes. In other examples, all the valve 100, pole pieces 2, intermediate bar 3, aspiration inlets 4, aspiration chambers 9, and aspiration outlets 5 may be made from any materials such as composite, metal alloys, and by mechanical processes such as machining, casting, and molding that are used to make such components. The valve 100 may be manufactured separately from the aspiration inlet 4, aspiration chamber 9, and aspiration outlet 5, and all the components may be fastened together mechanically. Alternatively, the valve 100, aspiration inlet 4, aspiration chamber 9, and aspiration outlet may all be made integral as part of the same component by machining, casting, molding, or otherwise creating all the features and components as a whole.

FIG. 3 is a section view of an exemplary design of the valve 100 taken along line 10 of FIG. 2. As shown in the example in FIG. 3, the valve 100 is mounted between two mounting plates 7 and further includes an aspiration chamber 9 connected to the aspiration inlets 4. In the exemplary design, the aspiration inlet 4 further consists of two segments: a larger recessed inlet 4a which allows for air to be drawn into the aspiration chamber 9 more easily, and an extended channel 4b protruding into the aspiration chamber 9 and which directs air into the top of the aspiration chamber 9. In the example, the recessed inlet 4a portion enables air to enter into the aspiration inlet 4, even if the mounting plates 7 mounted to the valve 100 extend over the aspiration inlet 4. The aspiration inlet 4 may also be constructed to have an extended air inlet channel 4b which may allow for air to flow through the aspiration chamber 9 even if media buildup occurs at the base of the aspiration chamber 9 by directing air flow above the aspiration outlet 5. In some embodiments, the extended air inlet channel 4b may prevent media build up within the aspiration chamber 9 by directing the flow of the air entering the aspiration chamber 9 above the aspiration outlet 5. The aspiration chamber 9 may further be constructed with a geometry that acts to filter the air—a debris collection zone 8—in which debris having more inertia than that of the air travel may fall out of the path of the air flow.

As shown in the exemplary design in FIG. 3, in operation, the wheel blast unit draws air into the valve 100 through the plurality of aspiration inlets 4 and which may produce a Venturi force within the aspiration chamber 9. This force draws air through the aspiration inlet 4, into the aspiration chamber 9 along the path indicated by the arrows 15 in FIG. 3.

First, the air travels through the plurality of aspiration inlets 4 through the opening provided by the aspiration inlet recess 4a. The air flow then travels from the opening of the extended inlet channel 4b, through the aspiration chamber 9, to the aspiration outlet 5, but before exiting the valve 100 through the aspiration outlet 5, the air flow passes geometry configured to filter debris from the air flow, or debris collection zone 8 located within the aspiration chamber 9. When passing through the debris collection zone 8, debris that is drawn into the aspiration chamber 9 from the environment, having a similar velocity as the air flow yet being heavier than the air flow and thus having a higher inertia than the air flow, may fall into the debris collection zone 8. Through this configuration, debris may be prevented from entering the media flow, which may prevent the peening media from being compromised by debris.

The air then flows through the aspiration outlet 5 and around a media barrier 6. The media barrier 6 may prevent media from the peening flow from entering the aspiration chamber 9 and inhibiting proper air flow.

This air flow, as it exits the aspiration outlet 5, provides a passive source of air aspiration to the shot peening system, preventing unfavorable suction or negative pressure from the wheel blast fans, which would otherwise draw shot media through the working gap and affect the shot peening parameters. Additionally, the air flows across the surface of the pole piece 2, acting as a cooling air current for the engine assembly. This secondary cooling aids in increasing the operating life of the valve.

While this disclosure has described certain examples, it will be understood that the claims are not intended to be limited to these examples except as explicitly recited in the claims. On the contrary, the instant disclosure is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the disclosure. Furthermore, in the detailed description of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, it will be obvious to one of ordinary skill in the art that systems and methods consistent with this disclosure may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure various aspects of the present disclosure.

Claims

1. An apparatus for controlling a flow of media comprising: a housing;a working gap within the housing configured to regulate the flow of media into the housing and out of the housing, the working gap further defining a perimeter within the housing;at least one inlet on the housing substantially outside of the working gap;at least one aspiration chamber within the housing connected to the at least one inlet; andat least one outlet on the housing connected to the at least one aspiration chamber, the outlet substantially within the working gap.

2. The apparatus of claim 1, wherein the inlet further defines a recess on a surface of the housing.

3. The apparatus of claim 1, wherein the inlet further comprises an extended channel protruding into the aspiration chamber.

4. The apparatus of claim 1, wherein the aspiration chamber further defines an air filtering geometry.

5. The apparatus of claim 1, wherein the outlet further comprises a media barrier located substantially between the outlet and the working gap.

6. The apparatus of claim 1, wherein the apparatus further comprises: at least one pole piece located substantially on the perimeter of the working gap; andat least one intermediate bar located substantially within the perimeter of the working gap.

7. The apparatus of claim 6, wherein at least one of the pole piece or intermediate bar are magnetically charged.

8. The apparatus of claim 6, wherein: the housing further comprises: a first side configured to receive media from a media hopper; anda second side configured to mate with a connection to a media blast unit;the at least one pole piece and the at least one intermediate bar are substantially fixed within the working gap at a point between the first side of the housing and the second side of the housing; andthe at least one outlet within the working gap is on the second side of the housing within the working gap.

9. An apparatus for controlling a flow of media comprising: a housing;a working gap within the housing configured to accept the flow of media into the housing and out of the housing the working gap further defining a perimeter within the housing;at least one inlet on the housing substantially outside of the working gap, the inlet defining a recessed portion and an extended channel;at least one aspiration chamber within the housing further comprising: a first end;an air filtering geometry; anda second end;wherein the first end is connected to the at least one inlet and the extended channel of the at least one inlet extends into the at least one aspiration chamber; andat least one outlet on the housing connected to the second end of the at least one aspiration chamber, the at least one outlet located substantially within the working gap, the at least one outlet further comprising a media barrier substantially between the outlet and the working gap.

10. The apparatus of claim 9, wherein the apparatus further comprises: at least one pole piece located substantially on the perimeter of the working gap; andat least one intermediate bar located substantially within the perimeter of the working gap.

11. The apparatus of claim 10, wherein at least one of the pole piece or intermediate bar are magnetically charged.

12. The apparatus of claim 10, wherein: the housing further comprises: a first side configured to receive media from a media hopper; anda second side configured to mate with a connection to a media blast unit;the at least one pole piece and the at least one intermediate bar are substantially fixed within the working gap at a point between the first side of the housing and the second side of the housing; andthe at least one outlet within the working gap is on the second side of the housing within the working gap.

13. A method for reducing negative pressure inherent to media flow in shot peening comprising the steps: providing an apparatus configured to regulate the flow of media, the apparatus further comprising: a housing further comprising: a first side configured to receive media from a media hopper; anda second side configured to mate with a connection to a media blast unit;a working gap configured to enable the flow of media between the first side and the second side;at least one inlet on the housing located substantially outside of the working gap;at least one aspiration chamber connected to the inlet; andat least one outlet on the housing connected to the aspiration chamber, the outlet located substantially within the working gap;connecting the apparatus housing on the first side to the media hopper;connecting the apparatus housing on the second side to the media blast unit; andsetting the apparatus to a closed position, wherein; when the apparatus is in the closed position it does not allow flow of media; anda negative pressure created by the media blast unit is relieved by air flowing through the at least one inlet, into the at least one aspiration chamber, and out from the at least one outlet towards the media blast unit, relieving the negative pressure.